Glue UHMW to aluminum?

[torker]

I have to glue (or something) some uhmw into 1/2" wide by 1/8" deep slots in aluminum. I was going to run screws in from the back but the screws will stick out too far into the plastic. I was wondering if the P-tex sticks used for ski base repairs would be compatible with uhmw? Drill a hole in the back of the alu and melt P-tex into the holes, gluing the inserts in. Or would some type of epoxy work for this? Thanks!
Russ

[Joel]

It looks like epoxy might do it, but there is some prep to consider:

http://www.garlandmfg.com/plastics/bonding.html

I don't know how your plastic will be loaded, but if it is in shear, why not use the pointy tips of short screws through the back to help maintain position. This would make the glues job much easier.

[pantaz]

Instead of threading screws into the UHMW, go the other way. Counterbore the plastic and use a small flat-head screw. That should get the screw head below the 1/8" recess in the aluminum.

[gunsmith]

I deal with UH all the time and as far as I have been told by the mfg. GE there is no adhesive for it. I have seen it welded to it's self however. But your question is fastening to aluminum. If you don't want to use mechanical fasteners then I would be using double sided machinist tape. Several grades available. It works well. I nearly have to destroy what I'm doing sometimes to free the UHMW item I have machined from it's backer.

[Jpfalt]

In my last go round with UHMW and aluminum, I roughed the aluminum and plastic with 80 grit sanding cloth, wetted the aluminum slightly with a damp rag and then clamped the assembly together with "Gorilla Glue". It seems to be holding well. Gorilla Glue is a urethane based product that cures when exposed to moisture. It will also foam to fill voids.

[torker]

Thanks for the advice guys! Looks like there are several options. This is mostly a "looks" thing. I don't really want any screws showing from the front and was going to mill it down nearly flush after I got it anchored down. There won't be much room for anything from the back. Had no idea machinists tape even existed. Sounds like handy stuff! I tried melting some together tonite and it turned all brown (was yellow). Think I'll try the roughing it up and epoxy.
jp...where the heck do you get Gorrilla Glue...I've never seen it up here? Thanks.
Russ

[rsr911]

I have several adhesives for UHMW, however most of them work best with corona treatment. If you'd like I can test a few on standard non-treated PE. Most outdoor printed banners are PE, and some (litho-poly) are a blend of LMW and HMW. UHMW is a little more difficult to stick to but it's still possible. Shoot me an email offline rsr911 at neo.rr.com and we can discuss what I have available. In your case the best bet is probably a heat seal adhesive but I've got some really good PSA's that might do the trick as well. A lot depends on the force generated on the part. Is it shear, peel or both? One of the adhesives I produce is for Santoprene boding to aluminum. Santoprene is a dog to stick to but this heat seal adhesive has over 45lbs per linear inch peel and a very high shear rate. It's heat seel but if you could bake the assembly in an oven, drop in the PE and apply pressure (weight) it would hold great. I can even give you free samples to test.

-Christian

[Joel]

Russ, Gorilla glue is a waterproof polyurethane glue marketed for woodworkers. It is available any woodworkers supply, Home Depot, etc.

http://www.gorillaglue.com/gGlue.html

[torker]

Thanks Joel! I'll have to see if that is sold anywhere around here....sounds interesting.
rsr...check your mail!
Russ

[Thrud]

Russ
Loctite has some special ureathane glues for plastics to glue SS needles into LDPE syringes and other difficult to bond plastics that you may want to investigate. These glues typicaly have << 6000PSI bond strength and fairly good peel properties so they may be able to help. The gun for these glues is about $40, the nozzles are about $15/12 and the glues range in price from dirt cheap to $60/oz. The glues auto-mix as they are dispensed by the gun.

I would contact Loctite directly and ask for assistance.

[Techtchr]

This may not survive the "looks good" test but it is another possible alternative. Drill and countersink the aluminum as if you were installing a flathead screw. Drill the UHMW to line up with the holes in the alum. insert short pieces of plastic welding rod and plastic weld into place. Should make a fairly strong mechanical fastener.
Matt

[Steve Stube]

Loc Tite Depend. You can do a lot of glue ups with the $24.00 kit. I haven't found anything yet it won't bond.

[torker]

Geez...It's a jungle out there when you need to glue something huh? Thanks for all the replies! This is for a "bling" billet hotrod part so it's gotta look good. Might have to make up a sacrificial piece to test some of this stuff. Thanks again!
Russ

[Eric Nelson]

I've worked with this material before -- try VHB (Very High Bond) from either 3M or Saint-Gobain.

It works well with UHMW, one of the only adhesives that does.

Check this site for more information: http://www.garlandmfg.com/plastics/pstape.html

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