I have a "classic" japanese motorbike which has been recovered from a
damp barn after 10 years.

Main obvious problem was the fuel tap had been left on and the carb
float needles gummed shut. Having part filled it with fuel, taken it
for MOT and failed on rusty fork stanchions and sticky brakes which I
have fixed I now find two small petrol leaks from the fuel tank.

Someone has plainly tried to fix this in the past as there is lots of
what looks like polyester resin littering the tank. I have shaken an
old chain about to break up most of the plastic but it precludes
attempting a repair from inside with the likes of POR15.

So I have decided to attempt to solder a repair and then float a piece
of brass or copper plate over the repairs.

I don't want to use a flame to avoid damaging the paint work or
distortion, does anyone think a 400W electric soldering iron will have
enough power? I ask because I will have to buy one or a big lump of
copper to heat up.

Any other tips, like what solder (I have some old 60/40) or flux might
be best.

AJH

Problem is, how good is the rest of the tank. it could be rusty all over the
place. If you fix one hole there could be another one almost through
already.
Brian

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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
wrote in message
...
I have a "classic" japanese motorbike which has been recovered from a
damp barn after 10 years.

Main obvious problem was the fuel tap had been left on and the carb
float needles gummed shut. Having part filled it with fuel, taken it
for MOT and failed on rusty fork stanchions and sticky brakes which I
have fixed I now find two small petrol leaks from the fuel tank.

Someone has plainly tried to fix this in the past as there is lots of
what looks like polyester resin littering the tank. I have shaken an
old chain about to break up most of the plastic but it precludes
attempting a repair from inside with the likes of POR15.

So I have decided to attempt to solder a repair and then float a piece
of brass or copper plate over the repairs.

I don't want to use a flame to avoid damaging the paint work or
distortion, does anyone think a 400W electric soldering iron will have
enough power? I ask because I will have to buy one or a big lump of
copper to heat up.

Any other tips, like what solder (I have some old 60/40) or flux might
be best.

AJH

On 13/11/2017 11:51, wrote:
I have a "classic" japanese motorbike which has been recovered from a
damp barn after 10 years.

Main obvious problem was the fuel tap had been left on and the carb
float needles gummed shut. Having part filled it with fuel, taken it
for MOT and failed on rusty fork stanchions and sticky brakes which I
have fixed I now find two small petrol leaks from the fuel tank.

Someone has plainly tried to fix this in the past as there is lots of
what looks like polyester resin littering the tank. I have shaken an
old chain about to break up most of the plastic but it precludes
attempting a repair from inside with the likes of POR15.

So I have decided to attempt to solder a repair and then float a piece
of brass or copper plate over the repairs.

I don't want to use a flame to avoid damaging the paint work or
distortion, does anyone think a 400W electric soldering iron will have
enough power? I ask because I will have to buy one or a big lump of
copper to heat up.

Any other tips, like what solder (I have some old 60/40) or flux might
be best.

AJH

Why do you think POR15 or similar wont work? I have used "Frosts Tank
slop" which I believe is the same thing in a Land rover tank a SPO had
attempted to seal with something else. I used the chain method along
with some brick cleaner to clean it out and it remained leak free for
the ten years I kept the vehicle.

Mike

On Mon, 13 Nov 2017 12:18:01 +0000, Muddymike
wrote:

Why do you think POR15 or similar wont work? I have used "Frosts Tank
slop" which I believe is the same thing in a Land rover tank a SPO had
attempted to seal with something else. I used the chain method along
with some brick cleaner to clean it out and it remained leak free for
the ten years I kept the vehicle.

Mainly because of the poorly adhering resin already in the tank. I
don't preclude the idea.

When you used brick acid did it not react with the steel? I have tried
citric acid so far and an attempting to get the broken pieces of resin
out.

I too have successfully used POR15 on my 101 tank, I first heated it
to separate the solder holding the carrier from the tank, cleaned the
inside with the cleaner from the POR15 kit, wired brushed back to
steel and then brazed obvious holes and applied a thin fibreglass
scrim and epoxy which also glued it to the carrier. I then treated it
with the POR15 and it held up till I sold the LR. It was quite
expensive though, which is why I thought solder may be better and
cheaper.

AJH

On Mon, 13 Nov 2017 11:57:09 -0000, "Brian Gaff"
wrote:

Problem is, how good is the rest of the tank. it could be rusty all over the
place. If you fix one hole there could be another one almost through
already.


That's a risk but from what I can see the rest of the inside looks
clean steel, both rust perforations are in a similar position near
seams at the rear of the tank on each side. My guess is that moisture
accumulated in that part of the tank and rotted through.

AJH

On Monday, 13 November 2017 13:28:25 UTC, wrote:
On Mon, 13 Nov 2017 12:18:01 +0000, Muddymike
wrote:

Why do you think POR15 or similar wont work? I have used "Frosts Tank
slop" which I believe is the same thing in a Land rover tank a SPO had
attempted to seal with something else. I used the chain method along
with some brick cleaner to clean it out and it remained leak free for
the ten years I kept the vehicle.

Mainly because of the poorly adhering resin already in the tank. I
don't preclude the idea.

When you used brick acid did it not react with the steel? I have tried
citric acid so far and an attempting to get the broken pieces of resin
out.

I too have successfully used POR15 on my 101 tank, I first heated it
to separate the solder holding the carrier from the tank, cleaned the
inside with the cleaner from the POR15 kit, wired brushed back to
steel and then brazed obvious holes and applied a thin fibreglass
scrim and epoxy which also glued it to the carrier. I then treated it
with the POR15 and it held up till I sold the LR. It was quite
expensive though, which is why I thought solder may be better and
cheaper.

AJH

Brick acid works to derust steel. It will attack steel, but by the time the rust is gone and you take it out there isn't a noticeable amount of attack. Leave it longer at your peril.


NT

On Mon, 13 Nov 2017 13:28:20 +0000, wrote:


When you used brick acid did it not react with the steel? I have tried
citric acid so far and an attempting to get the broken pieces of resin
out.

Hydrochloric acid brick acid) will react with the steel but slowly
compared with the rust areas. Brick acid is about 30% concentration
which is enough to produce nasty fumes and de rust within minutes.
Pickling acid used by metal finishers is usually hydrochloric acid at
about 15% concentration and about 20 mins pickling time. This will
remove rust but cause very little loss of good steel. However,
pickling leaves the steel surface very active and prone to surface
rusting. Phosphoric acid takes much longer but leaves a non-reacting
surface.

You don't want to use acid pickling if the inside surface still has
resin remains as the acid won't remove them but may track underneath
and cause further corrosion.

I've seen flame brazing and silver soldering of old motorcycle tanks
done with minimal damage to paintwork by draping the tank other than
in the work area in wet towels and quickly using an oxyacetylene flame
in the small area to be repaired. That was, however, done by a very
skilled welder.

(I've also watched, from a distance, as a similar repair was carried
out on an old BSA tank in the "Yang Po Motor manufactury and
construction workshop", a small tin hut in Jurong. When it was
suggested we would leave the bike for a day to allow them to vent the
tank the cheerful mechanic said "no need" , carefully put out his
cigarette and attacked the leaking tank still on the bike with an oxy
acetylene flame - which was why we ran some distance. The photo I
took (from said distance) shows him happily welding away as a plume of
petrol vapour screamed from the small vent in the fuel filler cap. To
my surprise not only did he survive but the tank (still on the bike)
was neatly welded.) I wouldn't suggest doing this.

On Mon, 13 Nov 2017 15:53:17 +0000, Peter Parry
wrote:

You don't want to use acid pickling if the inside surface still has
resin remains as the acid won't remove them but may track underneath
and cause further corrosion.

As the I can feel the broken remains of resin in the seams through
the level sender hole I realise I cannot get the resin out of the
narrow sections, also as the tank leaks the resin may have been
effective once but has failed.

This is another reason for attempting an external repair.

If I can successfully tin the 2 small areas of steel with the holes in
them I will be able to solder a preformed bit of copper over it.

So back to the soldering iron question...


AJH

On Mon, 13 Nov 2017 16:00:35 +0000
wrote:

On Mon, 13 Nov 2017 15:53:17 +0000, Peter Parry
wrote:

You don't want to use acid pickling if the inside surface still has
resin remains as the acid won't remove them but may track underneath
and cause further corrosion.

As the I can feel the broken remains of resin in the seams through
the level sender hole I realise I cannot get the resin out of the
narrow sections, also as the tank leaks the resin may have been
effective once but has failed.

Have you tried whacking the outside where the resin is with a rubber
hammer? That might be enough to get it to flake off without causing
much damage.

"Rob Morley" wrote in message
news:20171115162657.13b837fb@Mars...
On Mon, 13 Nov 2017 16:00:35 +0000
wrote:

On Mon, 13 Nov 2017 15:53:17 +0000, Peter Parry
wrote:

You don't want to use acid pickling if the inside surface still has
resin remains as the acid won't remove them but may track underneath
and cause further corrosion.

As the I can feel the broken remains of resin in the seams through
the level sender hole I realise I cannot get the resin out of the
narrow sections, also as the tank leaks the resin may have been
effective once but has failed.

Have you tried whacking the outside where the resin is with a rubber
hammer? That might be enough to get it to flake off without causing
much damage.



you can get a remover for that, personally never used it but told it does
work

https://www.mandp.co.uk/petseal-ultr...l-solvent.html

On Wed, 15 Nov 2017 16:26:57 +0000, Rob Morley wrote:

Have you tried whacking the outside where the resin is with a rubber
hammer? That might be enough to get it to flake off without causing
much damage.

This is a method I have heard of: Place abrasive in tank, 30%--50% full. Use
grit 1-2mm, Spax screws, broken glass, ... plus 0.5 - 1 liter petroleum. Wedge
tank in cement mixer with pillows. Let run 30 to 90 minutes.


https://youtu.be/aJuGLHToRGs

https://youtu.be/zxBWcxCdNWw

Thomas Prufer

Thomas Prufer wrote:

Place abrasive in tank, 30%--50% full. Use grit 1-2mm, Spax screws,
broken glass, ... plus 0.5 - 1 liter petroleum. Wedge tank in cement
mixer with pillows. Let run 30 to 90 minutes.

Pour into cocktail glasses with salted rim, and add sparkler?

On Wed, 15 Nov 2017 19:02:26 +0100, Thomas Prufer
wrote:

On Wed, 15 Nov 2017 16:26:57 +0000, Rob Morley wrote:

Have you tried whacking the outside where the resin is with a rubber
hammer? That might be enough to get it to flake off without causing
much damage.

This is a method I have heard of: Place abrasive in tank, 30%--50% full. Use
grit 1-2mm, Spax screws, broken glass, ... plus 0.5 - 1 liter petroleum. Wedge
tank in cement mixer with pillows. Let run 30 to 90 minutes.


https://youtu.be/aJuGLHToRGs

https://youtu.be/zxBWcxCdNWw

Thomas Prufer

Thanks, that looks interesting and doable if the solder method doesn't
work.

AJH

On Wed, 15 Nov 2017 17:23:01 -0000, "Mark" wrote:


"Rob Morley" wrote in message
news:20171115162657.13b837fb@Mars...

Have you tried whacking the outside where the resin is with a rubber
hammer? That might be enough to get it to flake off without causing
much damage.

I've got most of it out but I don't think anything mechanical will get
it out of the narrow sections and seams.



you can get a remover for that, personally never used it but told it does
work

https://www.mandp.co.uk/petseal-ultr...l-solvent.html

Useful to know but a bit expensive.

On Wed, 15 Nov 2017 19:08:00 +0000, Andy Burns wrote:

Thomas Prufer wrote:

Place abrasive in tank, 30%--50% full. Use grit 1-2mm, Spax screws,
broken glass, ... plus 0.5 - 1 liter petroleum. Wedge tank in cement
mixer with pillows. Let run 30 to 90 minutes.

Pour into cocktail glasses with salted rim, and add sparkler?

Hmmmh.
"Molotov Cocktail"? "Rusty Nail"? "Car bomb"? or something for Pterry's trolls?

Thomas Prufer

wrote in message
...
On Wed, 15 Nov 2017 17:23:01 -0000, "Mark" wrote:


"Rob Morley" wrote in message
news:20171115162657.13b837fb@Mars...

Have you tried whacking the outside where the resin is with a rubber
hammer? That might be enough to get it to flake off without causing
much damage.

I've got most of it out but I don't think anything mechanical will get
it out of the narrow sections and seams.



you can get a remover for that, personally never used it but told it does
work

https://www.mandp.co.uk/petseal-ultr...l-solvent.html

Useful to know but a bit expensive.

yes but if you dont remove the residue of the lining it will continue to
melt/ disintegrate and start blocking your fuel system


-

On Thu, 16 Nov 2017 17:14:13 -0000, "Mark" wrote:


yes but if you dont remove the residue of the lining it will continue to
melt/ disintegrate and start blocking your fuel system

It almost certainly won't melt as it is immune to petrol, there are
filters on the fuel tap so I'll keep an eye on them.

In the meanwhile I have soldered the two holes, adding a plate didn't
seem to work so I am relying on the solder alone.

I borrowed and old copper soldering iron heated separately with a blow
torch.

AJH

On 18/11/17 15:27, wrote:
It almost certainly won't melt as it is immune to petrol

ROFLMAO!

so is a 5 lire plastic fuel can.

That melts


--
€œBut what a weak barrier is truth when it stands in the way of an
hypothesis!€�

Mary Wollstonecraft