I did the armrest repair in the technical articles last week. My armrests came out great! The only problem is the JB weld apparently didn't stick to the hard plastic underneath so it all came apart again. Is there any other type of adhesive that might work better? Otherwise I might try getting a little piece of sandpaper in there to scuff up the hard plastic a little bit..

 

This should have been done from the start. Pretty much any adhesive like epoxy or JB weld bonds poorly to smooth surfaces.

 

Yeah, the epoxy needs a rough surface to bite into. Whatever adhesive you use is going to be the binder between the 2 surfaces, it will not meld the 2.

 

I used this stuff, not cheap but its been holding up for at least 5 years now
http://www.coolchem.com/

 

I used a product called "Heavy Duty Liquid Nails" from Home Depot. Comes in a tube and is applied with a caulking gun. About $2.50 a tube. Be careful with this stuff. Use it on a practise piece first to get the hang of it. This stuff is no joke.( I think I may have seen it at my local hardware store in hand squeezable tubes also.)

 

I'm doing this repair on my 89. The armrests are all clamped up now. I have my doughts that the Permatex heavy duty spray glue will hold. Don't ask why I used it .... other than it says it bonds to foam and plactic ..... and is HD. I did read all these posts weeks ago...


I ruffed up the surface on both the plactic and the rubber and their curing now. But I think the constant pulling from the vinyl wanting to return back might do me in. Oh well, l have pratice now......

These were originally made by just forming the vinyl and foam to a very smooth plastic core that had nothing for the foam to bite into... hence the problem. Some holes in the plastic might have done the trick.

 

there is a lot of fix it info on the net today..BUT.

when it comes to fixing things like arm rest. things that are soft and made to flex. ya cant use stuff that will not flex.

ya want STUFF that works. and stays fixed for years.

go to any shoe store/any walmart.. and get this stuff called Shoe Goo

this stuff will stick and stay fixed...dust off/clean. apply.keep your finger tip wet with water. and you can move it/push it to the place ya want.

hold in place with duck tape..let sit over night..and it's fixed.

when it comes time to remove it or replace it. it just as easy.

 

Well I added some support to the Pyrmatex I used. It was holding but I didn't trust it, so I drilled several 5/16th holes along the out side edge from the inside through the plastic and into the foam just a tad.

I rapped masking tape around the drill so It would only go through the plastic just a bit and into the foam. Then I used some epoxy made buy Smith bros. hobbies that I had ( good stuff ) and filled the holes and reclamped with thin wood and let it cure.
The epoxy worked it's way into the foam a bit and filled the holes.

It should have a good bite and hold.

If I don't post .... it's holding .

Edit: a couple of months plus and holding great.

 

Still holding.....

I think the holes drilled so it would have a better bite ( foam to plastic ) helped.

The foam on mine had a smooth skin on it.... so when I glued it back down to the plastic ( before drilling the holes ) the skin would seperate from the body of foam and pull away again.


BEFORE

 

Any longevity reports on which glue worked and stood the test of time?

 

I have a lot of experience with adhesives and what ArticWhiteZ said is correct. When gluing pliable materials that will flex and move in use you have to use an adhesive that remains flexible once cured. ShoeGoo works great, it just takes 12 hours or so to set. Don’t use any kind of epoxies or CA (superglue‘s), they cure to a hard consistency that is brittle and with crack and fail in that application.

 

thank you Jim. the shoo goo made total sense, just wasn’t sure of its holding power. does it stick to the foam also?

 

I've lost track of how many I've fixed with super glue. It works fine.

 

Sure thing, I’m yet to find something that ShoeGoo doesn’t adhere to

 

where did you get your adhesive experience?

 

A lifetime of building things that mainly were assembled with a variety of adhesives. My old workshop was stocked with various epoxies, CA glues, aliphatic resins, contact cement, etc, etc.

 

very cool. sounds like aerospace stuff

 

Definitely scuff it and maybe even use an adhesion promoter

 

im not entirely certain what an adhesion promoter is? is it essentially a degreaser?

 

Gorilla glue worked on mine. It is polyurethane and expands much like the original material inside the armrest. Drilling a few holes and letting the glue expand inside the holes seems like a great idea.

 

Not at all. Google it. It’s used on bare plastic to help paint stick. I’m not saying it’s a must in your application but you might should research whether it will help on your situation.

 

it appears to be designed specifically for paint. if added to the paint, it allows the paint to be more flexible for plastics, which probably expand more than metal. Also puts a thin layer of substrate down, which paint can stick to better. not finding anything about usage for glue, although one might consider paint a sort of glue I guess......

 

Adhesion promoter is not used only for paint and not only added to paint. You can buy adhesion promoter wipes or spray can.

If you go and buy 3m 2 part bumper repair epoxy it will say in the directions to be sure to use adhesion promoter before applying the epoxy.

Again in I dont know if it would help at all, I just know that I’ve seen paints and 2 part epoxies that recommend using it before hand.