Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

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Default car rust repair

I have a persistent rust problem on the lower edges of rear fenders
where the wheel well liner blocks access to the back side. The lower
edge seam wasn't watertight and rust has perforated the outer and
wheel well liner sheet metal below the factory sealer bead, which was
applied from inside after spot-welding and didn't reach down to the
joint. I dug out most of it so I could MIG weld patches without
igniting it.

Several local paint suppliers have suggested 3M 08852 Cavity Wax Plus
to coat the inside of my larger welded and smaller resin patches to
prevent or slow the so far yearly rust lines along their edges. LPS-3
wasn't up to the task, or I didn't coat the out-of-sight area well
enough with it. The Cavity Wax comes with long applicator tubes.

I'd like advice on if it really works, and how difficult it is to
remove if for some reason it doesn't and I need to weld in a larger
patch.

The clerk told me it's better than rubberized undercoating in the
wheel well. The suggested alternative there is spray can truck
bedliner, assuming it can be removed if necessary.
tia
-jsw


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Default car rust repair

On Wed, 30 Aug 2017 11:20:00 -0400, "Jim Wilkins"
wrote:

I have a persistent rust problem on the lower edges of rear fenders
where the wheel well liner blocks access to the back side. The lower
edge seam wasn't watertight and rust has perforated the outer and
wheel well liner sheet metal below the factory sealer bead, which was
applied from inside after spot-welding and didn't reach down to the
joint. I dug out most of it so I could MIG weld patches without
igniting it.

Several local paint suppliers have suggested 3M 08852 Cavity Wax Plus
to coat the inside of my larger welded and smaller resin patches to
prevent or slow the so far yearly rust lines along their edges. LPS-3
wasn't up to the task, or I didn't coat the out-of-sight area well
enough with it. The Cavity Wax comes with long applicator tubes.

I'd like advice on if it really works, and how difficult it is to
remove if for some reason it doesn't and I need to weld in a larger
patch.

The clerk told me it's better than rubberized undercoating in the
wheel well. The suggested alternative there is spray can truck
bedliner, assuming it can be removed if necessary.
tia
-jsw

If you don't get ALL of rhe rust out, it WILL come back - but a
Wax-Oil reatment will drive out moisture and seal moisture out - doing
a pretty good job of reducing rust. Bedliner just locks in any
moisture amd lets it rot from behind leavinf you a plastic fender.
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Default car rust repair

On Wed, 30 Aug 2017 21:27:09 -0400, wrote:

On Wed, 30 Aug 2017 11:20:00 -0400, "Jim Wilkins"
wrote:

I have a persistent rust problem on the lower edges of rear fenders
where the wheel well liner blocks access to the back side. The lower
edge seam wasn't watertight and rust has perforated the outer and
wheel well liner sheet metal below the factory sealer bead, which was
applied from inside after spot-welding and didn't reach down to the
joint. I dug out most of it so I could MIG weld patches without
igniting it.

Several local paint suppliers have suggested 3M 08852 Cavity Wax Plus
to coat the inside of my larger welded and smaller resin patches to
prevent or slow the so far yearly rust lines along their edges. LPS-3
wasn't up to the task, or I didn't coat the out-of-sight area well
enough with it. The Cavity Wax comes with long applicator tubes.

I'd like advice on if it really works, and how difficult it is to
remove if for some reason it doesn't and I need to weld in a larger
patch.

The clerk told me it's better than rubberized undercoating in the
wheel well. The suggested alternative there is spray can truck
bedliner, assuming it can be removed if necessary.
tia
-jsw

If you don't get ALL of rhe rust out, it WILL come back - but a
Wax-Oil reatment will drive out moisture and seal moisture out - doing
a pretty good job of reducing rust. Bedliner just locks in any
moisture amd lets it rot from behind leavinf you a plastic fender.


How well does phosphoric prep/etch/rust-converter work in this
application?

-
I am a Transfinancial--A rich person born in a poor person's body.
Please stop the hate by sending me money to resolve my money
identity disorder. --anon
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Default car rust repair

"Larry Jaques" wrote in message
...
On Wed, 30 Aug 2017 21:27:09 -0400, wrote:

On Wed, 30 Aug 2017 11:20:00 -0400, "Jim Wilkins"
wrote:

I have a persistent rust problem on the lower edges of rear fenders
where the wheel well liner blocks access to the back side. The
lower
edge seam wasn't watertight and rust has perforated the outer and
wheel well liner sheet metal below the factory sealer bead, which
was
applied from inside after spot-welding and didn't reach down to the
joint. I dug out most of it so I could MIG weld patches without
igniting it.

Several local paint suppliers have suggested 3M 08852 Cavity Wax
Plus
to coat the inside of my larger welded and smaller resin patches to
prevent or slow the so far yearly rust lines along their edges.
LPS-3
wasn't up to the task, or I didn't coat the out-of-sight area well
enough with it. The Cavity Wax comes with long applicator tubes.

I'd like advice on if it really works, and how difficult it is to
remove if for some reason it doesn't and I need to weld in a larger
patch.

The clerk told me it's better than rubberized undercoating in the
wheel well. The suggested alternative there is spray can truck
bedliner, assuming it can be removed if necessary.
tia
-jsw

If you don't get ALL of rhe rust out, it WILL come back - but a
Wax-Oil reatment will drive out moisture and seal moisture out -
doing
a pretty good job of reducing rust. Bedliner just locks in any
moisture amd lets it rot from behind leavinf you a plastic fender.


How well does phosphoric prep/etch/rust-converter work in this
application?


https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and asked
about it for exterior rust spots. The girl said it wasn't recommended
for that use, but didn't know why, nor have I seen a reason more
recently.

When there is access to both sides I weld in steel patches, otherwise
I sandblast all the rust off the exterior. In some cases my
sandblasted repairs have lasted a decade, possibly because the back of
the panel or bumper was still intact.

The problem here apears to be rust that broke through from the back,
because the fender lip joint wasn't sealed well enough. I can barely
see some of the damaged area from the inside, let alone sand it or
scrub off all the factory caulk. I don't want to apply something
flammable that I can't remove later to weld.

The dealer's body shop would replace the entire quarter panel, for
more than the value of the car.

-jsw


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Default car rust repair

Jim Wilkins wrote:
I have a persistent rust problem on the lower edges of rear fenders
where the wheel well liner blocks access to the back side. The lower
edge seam wasn't watertight and rust has perforated the outer and
wheel well liner sheet metal below the factory sealer bead, which was
applied from inside after spot-welding and didn't reach down to the
joint. I dug out most of it so I could MIG weld patches without
igniting it.

Several local paint suppliers have suggested 3M 08852 Cavity Wax Plus
to coat the inside of my larger welded and smaller resin patches to
prevent or slow the so far yearly rust lines along their edges. LPS-3
wasn't up to the task, or I didn't coat the out-of-sight area well
enough with it. The Cavity Wax comes with long applicator tubes.

I'd like advice on if it really works, and how difficult it is to
remove if for some reason it doesn't and I need to weld in a larger
patch.

The clerk told me it's better than rubberized undercoating in the
wheel well. The suggested alternative there is spray can truck
bedliner, assuming it can be removed if necessary.
tia
-jsw



Cavity wax is good stuff. Waxoyl is another good option.
Both spray in as a thin liquid and the carrier evaporates leaving behind
a thicker coating about like a heavy grease. Both are somewhat self
healing as well.

Both can be removed by heating with a heat gun, wiping off the majority
and using wax & grease remover to get the film off.

Have shot a LOT of both over the years. They both slow the rust WAY down.

Stay away from the rubberized stuff if you really want to stop rust.
That stuff tends to trap moisture under it. Bedliner is good IF there is
NO rust at all and you don't want to remove it.

--
Steve W.


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Default car rust repair

"Steve W." wrote in message
news
Jim Wilkins wrote:.....

Cavity wax is good stuff. Waxoyl is another good option.
Both spray in as a thin liquid and the carrier evaporates leaving
behind a thicker coating about like a heavy grease. Both are
somewhat self healing as well.

Both can be removed by heating with a heat gun, wiping off the
majority and using wax & grease remover to get the film off.

Have shot a LOT of both over the years. They both slow the rust WAY
down.

Stay away from the rubberized stuff if you really want to stop rust.
That stuff tends to trap moisture under it. Bedliner is good IF
there is NO rust at all and you don't want to remove it.

--
Steve W.


Thanks. That agrees with what the paint store clerks told me but I
can't tell how much of their advice is first or second hand. The
people who do this for a living now have the equipment for catalyzed
mixtures, which I don't.

Etching primer seems to be controversial. I sprayed topcoat directly
over it last time, a mistake that obscured whether or not it
contributed to the reappearance of rust. I'm searching for a simple
accelerated corrosion test that is more representative of real life
results than the old salt spray test.
https://en.wikipedia.org/wiki/Cyclic_corrosion_testing
The test in my college Materials Science course was to leave the
sample immersed in a jar on the shelf.


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Default car rust repair

"Jim Wilkins" wrote in message news
https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and asked
about it for exterior rust spots. The girl said it wasn't recommended
for that use, but didn't know why, nor have I seen a reason more
recently.
================================================== ===========

According to the can label and their website, POR-15 is not UV resistant so
it won't stand up to sunlight. It's ok on the underside of a car but not
the exterior. They have another product, POR-16 I think, that is more
expensive and rated for sunlight. A friend here in Maryland with occasional
winter road salt used a couple of quarts of POR-15 and some fiberglass cloth
to patch large rust holes in his Dad's Explorer, and we were amazed at how
well it worked structurally. Holes as large as 6"x6" in the wheel wells and
fenders. No peeling or cracking or any signs of further rust under the
POR-15. Four or five years later is still looked like the day he put it on,
but sadly his brother totaled the Explorer and stopped the test :-).

--
Regards,
Carl Ijames


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Default car rust repair

On Thu, 31 Aug 2017 12:52:19 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
.. .
On Wed, 30 Aug 2017 21:27:09 -0400, wrote:

On Wed, 30 Aug 2017 11:20:00 -0400, "Jim Wilkins"
wrote:

I have a persistent rust problem on the lower edges of rear fenders
where the wheel well liner blocks access to the back side. The
lower
edge seam wasn't watertight and rust has perforated the outer and
wheel well liner sheet metal below the factory sealer bead, which
was
applied from inside after spot-welding and didn't reach down to the
joint. I dug out most of it so I could MIG weld patches without
igniting it.

Several local paint suppliers have suggested 3M 08852 Cavity Wax
Plus
to coat the inside of my larger welded and smaller resin patches to
prevent or slow the so far yearly rust lines along their edges.
LPS-3
wasn't up to the task, or I didn't coat the out-of-sight area well
enough with it. The Cavity Wax comes with long applicator tubes.

I'd like advice on if it really works, and how difficult it is to
remove if for some reason it doesn't and I need to weld in a larger
patch.

The clerk told me it's better than rubberized undercoating in the
wheel well. The suggested alternative there is spray can truck
bedliner, assuming it can be removed if necessary.
tia
-jsw

If you don't get ALL of rhe rust out, it WILL come back - but a
Wax-Oil reatment will drive out moisture and seal moisture out -
doing
a pretty good job of reducing rust. Bedliner just locks in any
moisture amd lets it rot from behind leavinf you a plastic fender.


How well does phosphoric prep/etch/rust-converter work in this
application?


https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and asked
about it for exterior rust spots. The girl said it wasn't recommended
for that use, but didn't know why, nor have I seen a reason more
recently.


Por 15 is not UV stable. It has to be topcoated.

When there is access to both sides I weld in steel patches, otherwise
I sandblast all the rust off the exterior. In some cases my
sandblasted repairs have lasted a decade, possibly because the back of
the panel or bumper was still intact.

The problem here apears to be rust that broke through from the back,
because the fender lip joint wasn't sealed well enough. I can barely
see some of the damaged area from the inside, let alone sand it or
scrub off all the factory caulk. I don't want to apply something
flammable that I can't remove later to weld.

The dealer's body shop would replace the entire quarter panel, for
more than the value of the car.

-jsw

You can do the same - for a lot less. Just takes a lot of time and
work. There is NO OTHER WAY to totally eliminate that rust. It's like
cancer. With cancer you can shrink the tumour with radiation or chemo
- but it will likely come back. Or you can cut it out. If by cutting
it out COMPLETELY, the cancer can be cured. If any cancer cells get
away, it can come back. Exactly like rust
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Default car rust repair

On Thu, 31 Aug 2017 13:12:52 -0400, "Steve W."
wrote:

Jim Wilkins wrote:
I have a persistent rust problem on the lower edges of rear fenders
where the wheel well liner blocks access to the back side. The lower
edge seam wasn't watertight and rust has perforated the outer and
wheel well liner sheet metal below the factory sealer bead, which was
applied from inside after spot-welding and didn't reach down to the
joint. I dug out most of it so I could MIG weld patches without
igniting it.

Several local paint suppliers have suggested 3M 08852 Cavity Wax Plus
to coat the inside of my larger welded and smaller resin patches to
prevent or slow the so far yearly rust lines along their edges. LPS-3
wasn't up to the task, or I didn't coat the out-of-sight area well
enough with it. The Cavity Wax comes with long applicator tubes.

I'd like advice on if it really works, and how difficult it is to
remove if for some reason it doesn't and I need to weld in a larger
patch.

The clerk told me it's better than rubberized undercoating in the
wheel well. The suggested alternative there is spray can truck
bedliner, assuming it can be removed if necessary.
tia
-jsw



Cavity wax is good stuff. Waxoyl is another good option.
Both spray in as a thin liquid and the carrier evaporates leaving behind
a thicker coating about like a heavy grease. Both are somewhat self
healing as well.

Both can be removed by heating with a heat gun, wiping off the majority
and using wax & grease remover to get the film off.

Have shot a LOT of both over the years. They both slow the rust WAY down.

Stay away from the rubberized stuff if you really want to stop rust.
That stuff tends to trap moisture under it. Bedliner is good IF there is
NO rust at all and you don't want to remove it.

Bed liner is only good over a sound paint film.
Waxoyl works best on a clean solid surface, but does work reasonably
well on lightly rusted spots. Krown works better on rusted surfaces
but needs to be re-applied at least yearly as it does noy leave a
self-sealing coating. Cavity wax works good at slowing eust if the
rust is first "chased" with something similar to WD40 to drive out all
moisture, and wick the wax into the structure of the rust. Bacxk in
the early 80s Toyota had a campaign on Tercel rear suspension where a
penetrant and cavity wax were applied inside the rear suspension arms.
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Default car rust repair

On Thu, 31 Aug 2017 15:23:25 -0400, "Carl Ijames"
wrote:

"Jim Wilkins" wrote in message news
https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and asked
about it for exterior rust spots. The girl said it wasn't recommended
for that use, but didn't know why, nor have I seen a reason more
recently.
================================================= ============

According to the can label and their website, POR-15 is not UV resistant so
it won't stand up to sunlight. It's ok on the underside of a car but not
the exterior. They have another product, POR-16 I think, that is more
expensive and rated for sunlight. A friend here in Maryland with occasional
winter road salt used a couple of quarts of POR-15 and some fiberglass cloth
to patch large rust holes in his Dad's Explorer, and we were amazed at how
well it worked structurally. Holes as large as 6"x6" in the wheel wells and
fenders. No peeling or cracking or any signs of further rust under the
POR-15. Four or five years later is still looked like the day he put it on,
but sadly his brother totaled the Explorer and stopped the test :-).

Por 15 has (or at least HAD)"BlackCote" which can be applied over
the regular POR 15 to make it UV stable. Cannot be used alone.


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wrote in message
...
On Thu, 31 Aug 2017 15:23:25 -0400, "Carl Ijames"
wrote:

"Jim Wilkins" wrote in message news
https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and asked
about it for exterior rust spots. The girl said it wasn't
recommended
for that use, but didn't know why, nor have I seen a reason more
recently.
================================================ =============

According to the can label and their website, POR-15 is not UV
resistant so
it won't stand up to sunlight. It's ok on the underside of a car
but not
the exterior. They have another product, POR-16 I think, that is
more
expensive and rated for sunlight. A friend here in Maryland with
occasional
winter road salt used a couple of quarts of POR-15 and some
fiberglass cloth
to patch large rust holes in his Dad's Explorer, and we were amazed
at how
well it worked structurally. Holes as large as 6"x6" in the wheel
wells and
fenders. No peeling or cracking or any signs of further rust under
the
POR-15. Four or five years later is still looked like the day he
put it on,
but sadly his brother totaled the Explorer and stopped the test :-).

Por 15 has (or at least HAD)"BlackCote" which can be applied over
the regular POR 15 to make it UV stable. Cannot be used alone.


The advice I got from several paint shops was that Bondo Glass or
equivalent was the right thing to fill sandblasted pits and small
holes, with or without a thin first coat of etching primer. Then the
Cavity Wax would seal any perforations from the back side.

I cut some test coupons from new and rusted sheet metal to check the
long term durability of several coatings, but I have to redo the car
fairly soon with the best-sounding options before New England weather
cools too much. On August 21 I did a quick exploratory repair using
easily removed high-build primer as the filler and it's already
showing rust lines.

The sandblasted pits and welded patches I did on my truck 10-15 years
ago are still rust-free.

-jsw


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Default car rust repair

On Thu, 31 Aug 2017 18:10:03 -0400, "Jim Wilkins"
wrote:

wrote in message
.. .
On Thu, 31 Aug 2017 15:23:25 -0400, "Carl Ijames"
wrote:

"Jim Wilkins" wrote in message news
https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and asked
about it for exterior rust spots. The girl said it wasn't
recommended
for that use, but didn't know why, nor have I seen a reason more
recently.
=============================================== ==============

According to the can label and their website, POR-15 is not UV
resistant so
it won't stand up to sunlight. It's ok on the underside of a car
but not
the exterior. They have another product, POR-16 I think, that is
more
expensive and rated for sunlight. A friend here in Maryland with
occasional
winter road salt used a couple of quarts of POR-15 and some
fiberglass cloth
to patch large rust holes in his Dad's Explorer, and we were amazed
at how
well it worked structurally. Holes as large as 6"x6" in the wheel
wells and
fenders. No peeling or cracking or any signs of further rust under
the
POR-15. Four or five years later is still looked like the day he
put it on,
but sadly his brother totaled the Explorer and stopped the test :-).

Por 15 has (or at least HAD)"BlackCote" which can be applied over
the regular POR 15 to make it UV stable. Cannot be used alone.


The advice I got from several paint shops was that Bondo Glass or
equivalent was the right thing to fill sandblasted pits and small
holes, with or without a thin first coat of etching primer. Then the
Cavity Wax would seal any perforations from the back side.

I cut some test coupons from new and rusted sheet metal to check the
long term durability of several coatings, but I have to redo the car
fairly soon with the best-sounding options before New England weather
cools too much. On August 21 I did a quick exploratory repair using
easily removed high-build primer as the filler and it's already
showing rust lines.

The sandblasted pits and welded patches I did on my truck 10-15 years
ago are still rust-free.

-jsw

If you are patching with a fiberglass or plasric filler make sure it
uses an epoxy resin, not polyester. An epoxy/glass filler seals the
patch. Polyester filler is porous and does not seal out water. You can
use bondo to profile after the hole is patched.
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wrote in message
...
On Thu, 31 Aug 2017 18:10:03 -0400, "Jim Wilkins"
wrote:

wrote in message
. ..
On Thu, 31 Aug 2017 15:23:25 -0400, "Carl Ijames"
wrote:

"Jim Wilkins" wrote in message news
https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and
asked
about it for exterior rust spots. The girl said it wasn't
recommended
for that use, but didn't know why, nor have I seen a reason more
recently.
============================================== ===============

According to the can label and their website, POR-15 is not UV
resistant so
it won't stand up to sunlight. It's ok on the underside of a car
but not
the exterior. They have another product, POR-16 I think, that is
more
expensive and rated for sunlight. A friend here in Maryland with
occasional
winter road salt used a couple of quarts of POR-15 and some
fiberglass cloth
to patch large rust holes in his Dad's Explorer, and we were
amazed
at how
well it worked structurally. Holes as large as 6"x6" in the wheel
wells and
fenders. No peeling or cracking or any signs of further rust
under
the
POR-15. Four or five years later is still looked like the day he
put it on,
but sadly his brother totaled the Explorer and stopped the test
:-).
Por 15 has (or at least HAD)"BlackCote" which can be applied over
the regular POR 15 to make it UV stable. Cannot be used alone.


The advice I got from several paint shops was that Bondo Glass or
equivalent was the right thing to fill sandblasted pits and small
holes, with or without a thin first coat of etching primer. Then the
Cavity Wax would seal any perforations from the back side.

I cut some test coupons from new and rusted sheet metal to check the
long term durability of several coatings, but I have to redo the car
fairly soon with the best-sounding options before New England
weather
cools too much. On August 21 I did a quick exploratory repair using
easily removed high-build primer as the filler and it's already
showing rust lines.

The sandblasted pits and welded patches I did on my truck 10-15
years
ago are still rust-free.

-jsw

If you are patching with a fiberglass or plasric filler make sure it
uses an epoxy resin, not polyester. An epoxy/glass filler seals the
patch. Polyester filler is porous and does not seal out water. You
can
use bondo to profile after the hole is patched.


I did ask about that, and was told Bondo Glass is "different", and
somehow better, though it still needs rust converter or cavity wax on
the back to seal out water. It seems to be short fiberglass strands in
mainly dark green resin with little or no talc as in regular
bondo-type putty.

Two years ago I used JB Weld epoxy to fill the small holes. By spring
they were outlined in rust.

-jsw


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On Thu, 31 Aug 2017 22:00:00 -0400, "Jim Wilkins"
wrote:

wrote in message
.. .
On Thu, 31 Aug 2017 18:10:03 -0400, "Jim Wilkins"
wrote:

wrote in message
...
On Thu, 31 Aug 2017 15:23:25 -0400, "Carl Ijames"
wrote:

"Jim Wilkins" wrote in message news
https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and
asked
about it for exterior rust spots. The girl said it wasn't
recommended
for that use, but didn't know why, nor have I seen a reason more
recently.
============================================= ================

According to the can label and their website, POR-15 is not UV
resistant so
it won't stand up to sunlight. It's ok on the underside of a car
but not
the exterior. They have another product, POR-16 I think, that is
more
expensive and rated for sunlight. A friend here in Maryland with
occasional
winter road salt used a couple of quarts of POR-15 and some
fiberglass cloth
to patch large rust holes in his Dad's Explorer, and we were
amazed
at how
well it worked structurally. Holes as large as 6"x6" in the wheel
wells and
fenders. No peeling or cracking or any signs of further rust
under
the
POR-15. Four or five years later is still looked like the day he
put it on,
but sadly his brother totaled the Explorer and stopped the test
:-).
Por 15 has (or at least HAD)"BlackCote" which can be applied over
the regular POR 15 to make it UV stable. Cannot be used alone.

The advice I got from several paint shops was that Bondo Glass or
equivalent was the right thing to fill sandblasted pits and small
holes, with or without a thin first coat of etching primer. Then the
Cavity Wax would seal any perforations from the back side.

I cut some test coupons from new and rusted sheet metal to check the
long term durability of several coatings, but I have to redo the car
fairly soon with the best-sounding options before New England
weather
cools too much. On August 21 I did a quick exploratory repair using
easily removed high-build primer as the filler and it's already
showing rust lines.

The sandblasted pits and welded patches I did on my truck 10-15
years
ago are still rust-free.

-jsw

If you are patching with a fiberglass or plasric filler make sure it
uses an epoxy resin, not polyester. An epoxy/glass filler seals the
patch. Polyester filler is porous and does not seal out water. You
can
use bondo to profile after the hole is patched.


I did ask about that, and was told Bondo Glass is "different", and
somehow better, though it still needs rust converter or cavity wax on
the back to seal out water. It seems to be short fiberglass strands in
mainly dark green resin with little or no talc as in regular
bondo-type putty.

Two years ago I used JB Weld epoxy to fill the small holes. By spring
they were outlined in rust.

-jsw

It's still polyester Use marine or aircraft product - west system
epoxy and chop or woven glass mat to fill the hole. Cut out as much
rusted steel as possible and "bump it back" to make room fot the
filler. Grind the patch to flush or just below, then top with bondo
and sand to finish.Epoxy/glass is a bit of a buffer to sand out
smoothly.
  #15   Report Post  
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Default car rust repair

On Thu, 31 Aug 2017 12:52:19 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
.. .
On Wed, 30 Aug 2017 21:27:09 -0400, wrote:

On Wed, 30 Aug 2017 11:20:00 -0400, "Jim Wilkins"
wrote:

I have a persistent rust problem on the lower edges of rear fenders
where the wheel well liner blocks access to the back side. The
lower
edge seam wasn't watertight and rust has perforated the outer and
wheel well liner sheet metal below the factory sealer bead, which
was
applied from inside after spot-welding and didn't reach down to the
joint. I dug out most of it so I could MIG weld patches without
igniting it.

Several local paint suppliers have suggested 3M 08852 Cavity Wax
Plus
to coat the inside of my larger welded and smaller resin patches to
prevent or slow the so far yearly rust lines along their edges.
LPS-3
wasn't up to the task, or I didn't coat the out-of-sight area well
enough with it. The Cavity Wax comes with long applicator tubes.

I'd like advice on if it really works, and how difficult it is to
remove if for some reason it doesn't and I need to weld in a larger
patch.

The clerk told me it's better than rubberized undercoating in the
wheel well. The suggested alternative there is spray can truck
bedliner, assuming it can be removed if necessary.
tia
-jsw

If you don't get ALL of rhe rust out, it WILL come back - but a
Wax-Oil reatment will drive out moisture and seal moisture out -
doing
a pretty good job of reducing rust. Bedliner just locks in any
moisture amd lets it rot from behind leavinf you a plastic fender.


How well does phosphoric prep/etch/rust-converter work in this
application?


https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."


I was thinking Klean-Strip Phosphoric Prep and Etch. After buying
some mis-labeled anti-seize from Permatex, I'm pretty skittish about
buying any more of their products. They've bought out and ruined
quite a few product lines over the recent years. The Kleen-Strip is
for the porch uprights in the back, where they're cast into the cement
porch. That's about page 3 of my To-Do list.


When POR15 first came out I called their tech help number and asked
about it for exterior rust spots. The girl said it wasn't recommended
for that use, but didn't know why, nor have I seen a reason more
recently.


It sounds like one of the best products on the market for rust.


When there is access to both sides I weld in steel patches, otherwise
I sandblast all the rust off the exterior. In some cases my
sandblasted repairs have lasted a decade, possibly because the back of
the panel or bumper was still intact.


Yeah, that's the way to go if you can. Seein' as the car is worth so
much, maybe an investment in a quart of polyester resin is in order.
Bondo's maybe fifteen bucks now. I liked it for repairing rotted
window sills and porch posts on other people's houses.


The problem here apears to be rust that broke through from the back,
because the fender lip joint wasn't sealed well enough. I can barely
see some of the damaged area from the inside, let alone sand it or
scrub off all the factory caulk. I don't want to apply something
flammable that I can't remove later to weld.


It's that crystallized moisture you have there which causes the
problem. That and any alkaline crystals the state tosses on top to
make it stickier. I'm glad OR uses sand and crushed terra cotta
pots/roof tiles here, during our few snow days per year, if any.



The dealer's body shop would replace the entire quarter panel, for
more than the value of the car.


I still can't believe a local body shop wanted $3500 to paint my old
'90 F-150 in 2006. And that was to paint it the same color! I can
see why you're tackling the job yourself. It was expensive at Flynn's
Frame and Collision back in '85, when I got out of wrenching.

--
Tomorrow is the most important thing in life. Comes into us at midnight
very clean. It's perfect when it arrives and it puts itself in our hands.
It hopes we've learned something from yesterday.
-- John Wayne


  #17   Report Post  
Posted to rec.crafts.metalworking
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Posts: 5,888
Default car rust repair

wrote in message
...
On Thu, 31 Aug 2017 22:00:00 -0400, "Jim Wilkins"
wrote:

wrote in message
. ..
On Thu, 31 Aug 2017 18:10:03 -0400, "Jim Wilkins"
wrote:

wrote in message
m...
On Thu, 31 Aug 2017 15:23:25 -0400, "Carl Ijames"
wrote:

"Jim Wilkins" wrote in message
news
https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and
asked
about it for exterior rust spots. The girl said it wasn't
recommended
for that use, but didn't know why, nor have I seen a reason more
recently.
============================================ =================

According to the can label and their website, POR-15 is not UV
resistant so
it won't stand up to sunlight. It's ok on the underside of a
car
but not
the exterior. They have another product, POR-16 I think, that
is
more
expensive and rated for sunlight. A friend here in Maryland
with
occasional
winter road salt used a couple of quarts of POR-15 and some
fiberglass cloth
to patch large rust holes in his Dad's Explorer, and we were
amazed
at how
well it worked structurally. Holes as large as 6"x6" in the
wheel
wells and
fenders. No peeling or cracking or any signs of further rust
under
the
POR-15. Four or five years later is still looked like the day
he
put it on,
but sadly his brother totaled the Explorer and stopped the test
:-).
Por 15 has (or at least HAD)"BlackCote" which can be applied
over
the regular POR 15 to make it UV stable. Cannot be used alone.

The advice I got from several paint shops was that Bondo Glass or
equivalent was the right thing to fill sandblasted pits and small
holes, with or without a thin first coat of etching primer. Then
the
Cavity Wax would seal any perforations from the back side.

I cut some test coupons from new and rusted sheet metal to check
the
long term durability of several coatings, but I have to redo the
car
fairly soon with the best-sounding options before New England
weather
cools too much. On August 21 I did a quick exploratory repair
using
easily removed high-build primer as the filler and it's already
showing rust lines.

The sandblasted pits and welded patches I did on my truck 10-15
years
ago are still rust-free.

-jsw

If you are patching with a fiberglass or plasric filler make sure
it
uses an epoxy resin, not polyester. An epoxy/glass filler seals
the
patch. Polyester filler is porous and does not seal out water. You
can
use bondo to profile after the hole is patched.


I did ask about that, and was told Bondo Glass is "different", and
somehow better, though it still needs rust converter or cavity wax
on
the back to seal out water. It seems to be short fiberglass strands
in
mainly dark green resin with little or no talc as in regular
bondo-type putty.

Two years ago I used JB Weld epoxy to fill the small holes. By
spring
they were outlined in rust.

-jsw

It's still polyester Use marine or aircraft product - west system
epoxy and chop or woven glass mat to fill the hole. Cut out as much
rusted steel as possible and "bump it back" to make room fot the
filler. Grind the patch to flush or just below, then top with bondo
and sand to finish.Epoxy/glass is a bit of a buffer to sand out
smoothly.


I follow the Darwinian theory that the specialty auto parts suppliers
know and sell what's proven to work, if I can learn how to use it
correctly, and I haven't found an epoxy-fiberglass product in any of
them, although I've heard and read that it's better than polyester
since I started patching rust in the 1970's. JB Weld failed as a rust
pit filler for me.

I'm now experimenting with sandblasting and patching 1/2" punched and
depressed holes in a rusty piece of water heater shell in various
ways. Yesterday I applied Bondo Glass over one coat of etching primer,
today it will go directly on the sandblasted steel. Bumping back the
edges without warping the panel is much easier over the hardy hole on
the anvil.

-jsw


  #18   Report Post  
Posted to rec.crafts.metalworking
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Posts: 10,399
Default car rust repair

On Thu, 31 Aug 2017 21:02:48 -0400, wrote:

On Thu, 31 Aug 2017 18:10:03 -0400, "Jim Wilkins"
wrote:

wrote in message
. ..
On Thu, 31 Aug 2017 15:23:25 -0400, "Carl Ijames"
wrote:

"Jim Wilkins" wrote in message news
https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and asked
about it for exterior rust spots. The girl said it wasn't
recommended
for that use, but didn't know why, nor have I seen a reason more
recently.
============================================== ===============

According to the can label and their website, POR-15 is not UV
resistant so
it won't stand up to sunlight. It's ok on the underside of a car
but not
the exterior. They have another product, POR-16 I think, that is
more
expensive and rated for sunlight. A friend here in Maryland with
occasional
winter road salt used a couple of quarts of POR-15 and some
fiberglass cloth
to patch large rust holes in his Dad's Explorer, and we were amazed
at how
well it worked structurally. Holes as large as 6"x6" in the wheel
wells and
fenders. No peeling or cracking or any signs of further rust under
the
POR-15. Four or five years later is still looked like the day he
put it on,
but sadly his brother totaled the Explorer and stopped the test :-).
Por 15 has (or at least HAD)"BlackCote" which can be applied over
the regular POR 15 to make it UV stable. Cannot be used alone.


The advice I got from several paint shops was that Bondo Glass or
equivalent was the right thing to fill sandblasted pits and small
holes, with or without a thin first coat of etching primer. Then the
Cavity Wax would seal any perforations from the back side.

I cut some test coupons from new and rusted sheet metal to check the
long term durability of several coatings, but I have to redo the car
fairly soon with the best-sounding options before New England weather
cools too much. On August 21 I did a quick exploratory repair using
easily removed high-build primer as the filler and it's already
showing rust lines.

The sandblasted pits and welded patches I did on my truck 10-15 years
ago are still rust-free.

-jsw

If you are patching with a fiberglass or plasric filler make sure it
uses an epoxy resin, not polyester. An epoxy/glass filler seals the
patch. Polyester filler is porous and does not seal out water. You can
use bondo to profile after the hole is patched.


Well said!

Gunner, who does a lot of fiberglass work on boats


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  #19   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 5,888
Default car rust repair

"Gunner Asch" wrote in message
...
On Thu, 31 Aug 2017 21:02:48 -0400, wrote:

On Thu, 31 Aug 2017 18:10:03 -0400, "Jim Wilkins"
wrote:

wrote in message
...
On Thu, 31 Aug 2017 15:23:25 -0400, "Carl Ijames"
wrote:

"Jim Wilkins" wrote in message
news
https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and
asked
about it for exterior rust spots. The girl said it wasn't
recommended
for that use, but didn't know why, nor have I seen a reason more
recently.
============================================= ================

According to the can label and their website, POR-15 is not UV
resistant so
it won't stand up to sunlight. It's ok on the underside of a car
but not
the exterior. They have another product, POR-16 I think, that is
more
expensive and rated for sunlight. A friend here in Maryland with
occasional
winter road salt used a couple of quarts of POR-15 and some
fiberglass cloth
to patch large rust holes in his Dad's Explorer, and we were
amazed
at how
well it worked structurally. Holes as large as 6"x6" in the
wheel
wells and
fenders. No peeling or cracking or any signs of further rust
under
the
POR-15. Four or five years later is still looked like the day he
put it on,
but sadly his brother totaled the Explorer and stopped the test
:-).
Por 15 has (or at least HAD)"BlackCote" which can be applied
over
the regular POR 15 to make it UV stable. Cannot be used alone.

The advice I got from several paint shops was that Bondo Glass or
equivalent was the right thing to fill sandblasted pits and small
holes, with or without a thin first coat of etching primer. Then
the
Cavity Wax would seal any perforations from the back side.

I cut some test coupons from new and rusted sheet metal to check
the
long term durability of several coatings, but I have to redo the
car
fairly soon with the best-sounding options before New England
weather
cools too much. On August 21 I did a quick exploratory repair using
easily removed high-build primer as the filler and it's already
showing rust lines.

The sandblasted pits and welded patches I did on my truck 10-15
years
ago are still rust-free.

-jsw

If you are patching with a fiberglass or plasric filler make sure it
uses an epoxy resin, not polyester. An epoxy/glass filler seals the
patch. Polyester filler is porous and does not seal out water. You
can
use bondo to profile after the hole is patched.


Well said!

Gunner, who does a lot of fiberglass work on boats


If I had a good recommendation for a specific epoxy auto body rust
repair product I would be trying it. Instead the paint dealers and
body shop estimators tell me -nothing- will last for very long in New
England. If so, I want something I can remove later to safely weld.

I have sandblasted coupons of Bondo Glass over etch primer, BG over
bare steel, and a rust converter outside drying right now, and a 5%
salt water solution to test them with. The letter stamps made a sharp
impression in the sheet metal against a backup of scrap aluminum.

I started cutting down the Bondo Glass at the point where I would
cheese-grator the plain stuff, and pulled the patch out of the
recessed hole. The break was in the resin, not from the unprimed
steel. The next batch hardened like concrete overnight. It does NOT
sand down as easily as regular Bondo. The 1/16-1/8" layer I left on
the mixing cardboard can be bent quite far before it cracks.
-jsw


  #20   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 18,538
Default car rust repair

On Sat, 2 Sep 2017 11:50:21 -0400, "Jim Wilkins"
wrote:

"Gunner Asch" wrote in message
.. .
On Thu, 31 Aug 2017 21:02:48 -0400, wrote:

On Thu, 31 Aug 2017 18:10:03 -0400, "Jim Wilkins"
wrote:

wrote in message
m...
On Thu, 31 Aug 2017 15:23:25 -0400, "Carl Ijames"
wrote:

"Jim Wilkins" wrote in message
news
https://www.amazon.com/Permatex-8177.../dp/B000HBNX38
"Not recommended for automotive exterior sheet metal repairs."

When POR15 first came out I called their tech help number and
asked
about it for exterior rust spots. The girl said it wasn't
recommended
for that use, but didn't know why, nor have I seen a reason more
recently.
============================================ =================

According to the can label and their website, POR-15 is not UV
resistant so
it won't stand up to sunlight. It's ok on the underside of a car
but not
the exterior. They have another product, POR-16 I think, that is
more
expensive and rated for sunlight. A friend here in Maryland with
occasional
winter road salt used a couple of quarts of POR-15 and some
fiberglass cloth
to patch large rust holes in his Dad's Explorer, and we were
amazed
at how
well it worked structurally. Holes as large as 6"x6" in the
wheel
wells and
fenders. No peeling or cracking or any signs of further rust
under
the
POR-15. Four or five years later is still looked like the day he
put it on,
but sadly his brother totaled the Explorer and stopped the test
:-).
Por 15 has (or at least HAD)"BlackCote" which can be applied
over
the regular POR 15 to make it UV stable. Cannot be used alone.

The advice I got from several paint shops was that Bondo Glass or
equivalent was the right thing to fill sandblasted pits and small
holes, with or without a thin first coat of etching primer. Then
the
Cavity Wax would seal any perforations from the back side.

I cut some test coupons from new and rusted sheet metal to check
the
long term durability of several coatings, but I have to redo the
car
fairly soon with the best-sounding options before New England
weather
cools too much. On August 21 I did a quick exploratory repair using
easily removed high-build primer as the filler and it's already
showing rust lines.

The sandblasted pits and welded patches I did on my truck 10-15
years
ago are still rust-free.

-jsw

If you are patching with a fiberglass or plasric filler make sure it
uses an epoxy resin, not polyester. An epoxy/glass filler seals the
patch. Polyester filler is porous and does not seal out water. You
can
use bondo to profile after the hole is patched.


Well said!

Gunner, who does a lot of fiberglass work on boats


If I had a good recommendation for a specific epoxy auto body rust
repair product I would be trying it.

I gave you the recommendation. West systems epoxy and either chop mat
ot woven glass mat well filled and pressed securely into place over
the perforated metal, well cleaned on both sides if possible. Let the
resin soak through and get onto the back of the body material.

When the subframe rail on my 1980 Corolla rusted through - along with
part of the floor, I cut out the rail and replaced it with a factory
repair part by welding it to the solid framework ahead, and to what
was left of the floor. I then laid in a few layers of glass mat,
sayurating it well, and then applied the blue "shop cloth" paper
towels top and bottom,and then plastic film, and squeazed the patch to
make sure the resin had completely folled the mat and all air was
aqueased out. The shopcloth was fully saturated when finisged, and was
left in place. That floor patch lasted for years in the southern
Ontario rust belt. I used the same method on the 88 New Yotker floor
and on the TranSport after having the subframe welded.



Instead the paint dealers and
body shop estimators tell me -nothing- will last for very long in New
England. If so, I want something I can remove later to safely weld.


In the past I have repaired rusted bodywork just using bondo, and it
popped every time. Even over brazed patches the bondo eventually pops.

I've never had a fiberglass patch pop, although I suspect it WOULD pop
if the panel was bent in an accident.

I have sandblasted coupons of Bondo Glass over etch primer, BG over
bare steel, and a rust converter outside drying right now, and a 5%
salt water solution to test them with. The letter stamps made a sharp
impression in the sheet metal against a backup of scrap aluminum.


After doing some investigation it looks like "bondo Glass" is listed
as waterproof, even though it uses polyester resin and talc. If it is
virtually impossible to "cheeze geater" and a royal bitch to sand, it
may well do the same job as the epoxy and glass I used, if properly
applied. No guaranteee, as I have not tried that prodect

I started cutting down the Bondo Glass at the point where I would
cheese-grator the plain stuff, and pulled the patch out of the
recessed hole. The break was in the resin, not from the unprimed
steel. The next batch hardened like concrete overnight. It does NOT
sand down as easily as regular Bondo. The 1/16-1/8" layer I left on
the mixing cardboard can be bent quite far before it cracks.
-jsw




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Posts: 18,538
Default car rust repair

On Sun, 03 Sep 2017 21:40:34 -0700, Gunner Asch
wrote:

On Sat, 02 Sep 2017 22:18:56 -0400, wrote:


If you are patching with a fiberglass or plasric filler make sure it
uses an epoxy resin, not polyester. An epoxy/glass filler seals the
patch. Polyester filler is porous and does not seal out water. You
can
use bondo to profile after the hole is patched.

Well said!

Gunner, who does a lot of fiberglass work on boats

If I had a good recommendation for a specific epoxy auto body rust
repair product I would be trying it.

I gave you the recommendation. West systems epoxy and either chop mat
ot woven glass mat well filled and pressed securely into place over
the perforated metal, well cleaned on both sides if possible. Let the
resin soak through and get onto the back of the body material.


West systems is good..but ****merunning its expensive. And there are
other Epoxies (only use epoxy) that are much cheaper and work as well
OR better than West Systmes

http://www.thomasnet.com/southern-ca...7571208-1.html

I would recommend a Marine grade though....

https://www.ebay.com/sch/i.html?_fro...resin&_sacat=0


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I agree there are others out there that may be less expensived - or
mabee just "cheaper". West is a known entity - really can't go wrong
with it, while "brand X" may or may not be quality stuff.

If you have experience with another product that you know works, use
it. I'm just saying if you want to do the job, I know THIS works.

The composite aircraft guys generally use West around here.
  #23   Report Post  
Posted to rec.crafts.metalworking
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Posts: 10,399
Default car rust repair

On Mon, 04 Sep 2017 10:30:20 -0400, wrote:

West systems is good..but ****merunning its expensive. And there are
other Epoxies (only use epoxy) that are much cheaper and work as well
OR better than West Systmes

http://www.thomasnet.com/southern-ca...7571208-1.html

I would recommend a Marine grade though....

https://www.ebay.com/sch/i.html?_fro...resin&_sacat=0


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https://www.avast.com/antivirus

I agree there are others out there that may be less expensived - or
mabee just "cheaper". West is a known entity - really can't go wrong
with it, while "brand X" may or may not be quality stuff.

If you have experience with another product that you know works, use
it. I'm just saying if you want to do the job, I know THIS works.

The composite aircraft guys generally use West around here.



Glass people use a ****load of this around here....

http://www.epoxyusa.com/category_s/3.htm

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