I need to bond a small stip of UHMW plastic to 304 stainless steel. How?

Karl

Karl Townsend wrote:

I need to bond a small stip of UHMW plastic to 304 stainless steel. How?

Karl

Call Locktite or 3M? Pretty sure they have a glue or tape that will do
the job nicely. Can probably find all the selector info you need on
their sites too. Heck, Woodcraft sells a thin UHMW adhesive backed tape
for use on woodworking jigs and whatnot, perhaps you could just use
that.

On Wed, 5 Sep 2007 20:59:02 -0500, with neither quill nor qualm, "Karl
Townsend" quickly quoth:

I need to bond a small stip of UHMW plastic to 304 stainless steel. How?

Rivets!

================================================== =========
Save the Endangered Bouillons from being cubed!
================================================== =========

On Wed, 5 Sep 2007 20:59:02 -0500, "Karl Townsend"
wrote:

I need to bond a small stip of UHMW plastic to 304 stainless steel. How?

Best way is to buy a roll of self-adhesive UHMW tape - see McMaster
p.3328

If that won't work for you, McMaster has epoxy meant for bonding
difficult plastics on p.3295 - $55 for 1.7 ounces!

I've used the tape, it's cheap and works well, never tried the epoxy.

--
Ned Simmons

"Larry Jaques" wrote in message
...
On Wed, 5 Sep 2007 20:59:02 -0500, with neither quill nor qualm, "Karl
Townsend" quickly quoth:

I need to bond a small stip of UHMW plastic to 304 stainless steel. How?

Rivets!

================================================== =========
Save the Endangered Bouillons from being cubed!
================================================== =========

Proper thinking, Larry!

On Wed, 5 Sep 2007 22:49:01 -0700, with neither quill nor qualm, "Tom
Gardner" quickly quoth:


"Larry Jaques" wrote in message
.. .
On Wed, 5 Sep 2007 20:59:02 -0500, with neither quill nor qualm, "Karl
Townsend" quickly quoth:

I need to bond a small stip of UHMW plastic to 304 stainless steel. How?

Rivets!

================================================== =========
Save the Endangered Bouillons from being cubed!
================================================== =========

Proper thinking, Larry!

Which, for the bouillons or the metal (and mettle) in my reply? At
least the spamming Net Nazi won't get me for that post.

================================================== =========
Save the Endangered Bouillons from being cubed!
================================================== =========

"Larry Jaques" wrote in message
. ..
On Wed, 5 Sep 2007 20:59:02 -0500, with neither quill nor qualm,
"Karl Townsend" quickly quoth:

I need to bond a small stip of UHMW plastic to 304 stainless steel.
How?

Rivets!

There is another way (actually a couple).

A simple method is with a resiliant adhesive of the "pressure sensitive"
variety -- rubbery acrylamide glue or double-stick foam tape come to
mind. If there isn't much force in shear, foam tape works really well.

A "direct" bond can be made by surface etching the plastic. You can do
it yourself with a nasty chemical brew (I can post a copy if you wish),
or you can purchase polyethylene and teflon with a "treated surface" for
bonding. McMaster and MSC sell treated teflon... I haven't bought any
UHMW PE from them in that type, so I don't know what they have.

LLoyd

"Karl Townsend" wrote in message
anews.com...
I need to bond a small stip of UHMW plastic to 304 stainless steel. How?

Karl


vhb tape

http://www.uline.com/ProductDetail.a...10113&ref=6038

Lloyd E. Sponenburgh writes:

You can do
it yourself with a nasty chemical brew (I can post a copy if you wish),

I wish.

The surface prep for the purported glues for PE are pretty ordinary
solvents.

or you can purchase polyethylene and teflon with a "treated surface" for
bonding. McMaster and MSC sell treated teflon... I haven't bought any
UHMW PE from them in that type, so I don't know what they have.

Bondable Teflon is a chemically converted layer, not just etched.

I wasn't aware that PE can be so converted. I thought the McMaster item
just had a layer of pressure-sensitive adhesive applied to it.

"Karl Townsend" wrote in message
anews.com...
I need to bond a small stip of UHMW plastic to 304 stainless steel. How?

Karl

There's always more to this question than one thinks of.
Is it structural? What kind of tension or shear loads will it see?
How thick is the bond line?
What's the area/dimensions of the bond?
Are the surfaces flat or shaped?
Expected temperature range?
Other environmental conditions?
Will the joint have any kind of flex applied to it?

I've used all kinds of glues for things that work fine if the demands
aren't high.

Richard J Kinch fired this volley in
:

Lloyd E. Sponenburgh writes:

You can do
it yourself with a nasty chemical brew (I can post a copy if you
wish),

I wish.

The surface prep for the purported glues for PE are pretty ordinary
solvents.

or you can purchase polyethylene and teflon with a "treated surface"
for bonding. McMaster and MSC sell treated teflon... I haven't
bought any UHMW PE from them in that type, so I don't know what they
have.

Bondable Teflon is a chemically converted layer, not just etched.

Richard, when I said "etched" that was inexact. The surface IS etched,
but is also oxidized -- i.e. "converted". I have such a formula, and the
process is do-able in the home shop.

LLoyd

On Sep 7, 12:25 pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com

Richard, when I said "etched" that was inexact. The surface IS etched,
but is also oxidized -- i.e. "converted". I have such a formula, and the
process is do-able in the home shop.

LLoyd

You can also play a propane torch over the polyethylene and get the
surface to oxidize. Not as controlled a process , but it will help in
bonding to UHMW.

Dan

On Thu, 06 Sep 2007 12:36:38 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:


"Larry Jaques" wrote in message
...
On Wed, 5 Sep 2007 20:59:02 -0500, with neither quill nor qualm,
"Karl Townsend" quickly quoth:

I need to bond a small stip of UHMW plastic to 304 stainless steel.
How?

Rivets!

There is another way (actually a couple).

A simple method is with a resiliant adhesive of the "pressure sensitive"
variety -- rubbery acrylamide glue or double-stick foam tape come to
mind. If there isn't much force in shear, foam tape works really well.

A "direct" bond can be made by surface etching the plastic. You can do
it yourself with a nasty chemical brew (I can post a copy if you wish),


I'd like to see your etching recipe, Lloyd.

Don Foreman fired this volley in
:
I'd like to see your etching recipe, Lloyd.

This solution will work, albeit more slowly, on UHMW PE as well.

FWIW, I got this HERE from a past contributor.

It's nasty... use breathing protection or an exhaust hood, and work
carefully. Hexavalent chromates and bi-chromates are potent corrosives
and carcinogenic. And sulfuric acid ain't no warm puppy, either.

------------------

The solution of choice is a chromic/sulfuric acid solution:
Parts By Weight
H2SO4 (Sulfuric acid) 100
Na2Cr2O7 _2H2O (Sodium Dichromate) 5
H2O (Water) 8

The solution should be mixed with care as it is an extremely strong
oxidizer. When fresh, it is dark brown,
and gradually becomes dark green upon exposure to air and in use . a
practical indicator that it should be
replaced. The solution will naturally etch through a polyethylene
container and should be stored in safetyglass
bottles. Note that in past decades Emerson and Cuming manufactured
..Ecoprime PP. as a
recommended treatment for polyethylene prior to bonding. Though the
solution is no longer available, it
appears to be very similar to the mixture above as deduced from the
Material Safety Data Sheets.
The polyethylene sheets are cut from HDPE rod stock and turned on a
vacuum chuck to approximately
20-mils thickness. They are then rubbed with an acetone-soaked Kimwipe to
remove gross dirt and
organics, then placed in the etching solution. The disks are etched for
approximately 1 hour with
intermittent stirring, then rinsed for 5 minutes under warm running
water, and given a final rinse with
distilled water. Baking is not recommended for the surface-treated
polyethylene, nor is wiping the surface.
Instead, the windows should be blown dry with clean nitrogen gas. If a
bake is necessary to dry them, the
temperature should be kept at approximately 50 C.

Lloyd E. Sponenburgh writes:

I have such a formula, and the process is do-able in the home shop.

OK, that was my wish, that you post a copy.

Lloyd E. Sponenburgh writes:

H2SO4 (Sulfuric acid) 100

But what concentration is this acid supposed to be?

On Sep 7, 12:32 pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
...
The solution of choice is a chromic/sulfuric acid solution:
Parts By Weight
H2SO4 (Sulfuric acid) 100
Na2Cr2O7 _2H2O (Sodium Dichromate) 5
H2O (Water) 8
...

That was the cleaning agent of last resort for any baked-on mystery
crud on glassware back when I was a chemist, pre-EPA.

Coleman sold a patch kit containing an industrial adhesive that would
stick to their polyethylene canoes.

jw

On Fri, 07 Sep 2007 16:32:24 -0000, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Don Foreman fired this volley in
:
I'd like to see your etching recipe, Lloyd.

This solution will work, albeit more slowly, on UHMW PE as well.

FWIW, I got this HERE from a past contributor.

It's nasty... use breathing protection or an exhaust hood, and work
carefully. Hexavalent chromates and bi-chromates are potent corrosives
and carcinogenic. And sulfuric acid ain't no warm puppy, either.

------------------

The solution of choice is a chromic/sulfuric acid solution:
Parts By Weight
H2SO4 (Sulfuric acid) 100
Na2Cr2O7 _2H2O (Sodium Dichromate) 5
H2O (Water) 8

Thanks, Lloyd. Nasty stuff indeed, but archived for future reference.
Given the 8 parts of H20, I assume that the H2SO4 is 98% or anhydrous?
I don't know where I'd get that -- or the dichromate either.

Richard J Kinch fired this volley in
:

Lloyd E. Sponenburgh writes:

H2SO4 (Sulfuric acid) 100

But what concentration is this acid supposed to be?


lacking any other information, I'd assume 9lb/gal.

LLoyd

Don Foreman fired this volley in
:

Thanks, Lloyd. Nasty stuff indeed, but archived for future reference.
Given the 8 parts of H20, I assume that the H2SO4 is 98% or anhydrous?
I don't know where I'd get that -- or the dichromate either.

I'd have to ask more expert hands to do the calculations, but I think
potassium dichromate would serve, and it is readily available. In this
case, check out the several amateur pyrotechnic suppliers like Skylighter
or Firefox.

LLoyd

On Sep 5, 9:59 pm, "Karl Townsend"
wrote:
I need to bond a small stip ofUHMWplastic to 304 stainless steel. How?

Karl

Hi Karl,

I sell offcuts of UHMW on ebay and in major woodworking chains like
Lee Valley and Woodcraft.

You can't actually glue UH to anything if you want a durable, strong
joint, because UHmw is a closed molecule that won't even absorb water,
let alone the glue components you're trying to create a bond with.

The best you'll ever be able to achieve is an "atmosphere bond" with
self-adhesive tape. As has already been noted, if you don't have a
lot of shear strength needed, that may do all right for you.

You CAN weld UHMW, but it takes special equipment and a specialized
skill. Probably not worth it for a single job.

I think your original idea of using rivets is probably the best bet
for the job.

The idea of crazing the surface by etching it or using a propane torch
is iffy. UHMW melts almost at the same temperature that it ignites at
- you could have a real mess from that.

BTW, if the UH DOES melt, it smells like candles, but the drippings
are NOT wax. They'll cause 2nd and 3rd-degree burns. Be careful.

Eric

"Richard J Kinch" wrote:
Lloyd E. Sponenburgh writes:

I have such a formula, and the process is do-able in the home shop.

OK, that was my wish, that you post a copy.

I would also like to see this formula, having just bought some of the
slippery white stuff which I would like to eventually somewhat adhere to Cu.

Jon

Don Foreman" wrote:
On Fri, 07 Sep 2007 16:32:24 -0000, "Lloyd E. Sponenburgh" wrote:
The solution of choice is a chromic/sulfuric acid solution:
Parts By Weight
H2SO4 (Sulfuric acid) 100
Na2Cr2O7 _2H2O (Sodium Dichromate) 5
H2O (Water) 8

Thanks, Lloyd. Nasty stuff indeed, but archived for future reference.
Given the 8 parts of H20, I assume that the H2SO4 is 98% or anhydrous?
I don't know where I'd get that -- or the dichromate either.

Given that the formula also calls for water, you could theoretically use
diluted sulphuric, given that the amount of water was at least equal or less
than that required by the given ratios.

Jon

"Jon Danniken"
"Richard J Kinch" wrote:
Lloyd E. Sponenburgh writes:

I have such a formula, and the process is do-able in the home shop.

OK, that was my wish, that you post a copy.

I would also like to see this formula, having just bought some of the
slippery white stuff which I would like to eventually somewhat adhere to
Cu.

Whoops, cancel that, you gave the formula in a post further down the thread.

Jon