A question of bonding

Barney 5 said:

Does 3M make something that would be suitable?

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Yes they do.
First........what year is the car in question?




For a '73 on up......
"3M Panel Bonding Adhesive" I usually have a cartridge in my garage, but tonight I do not
Have plenty at work.........will get you a part number and photo tomorrow.

This will work just fine on SMC, Don't know about GRP???????? never tried it.
It will also bond metal panels as well and also works great on most all
late model flexible (non-fiberglass) bumper covers. Has a dispensing tube
to get to hard to reach areas.

I generally use it for Door and roof skins as well as wheel openings when
replacing 1/4 panels.

I did a C4 several months ago that the whole rear shell had come loose from the inner structure.

Stay tuned........................

3M, Fusor, and SEM all have 2 part adhesives designed specifically for bonding body panels and they are available at automotive paint stores. These adhesives are extremely strong and are used on most steel cars today in place of welding. The adhesive packs cost around $30-$50 but require special application guns which mix the 2 parts together and can cost upwards of $250 just for the gun. Each manufacturer has a different gun and mixing nozzle designed for their adhesive.
SEM has the least expensive gun at around $60. If you want to use 3M or Fusor, you might find a used guns on ebay.
There are a lot of adhesive choices in each brand depending on set time, thickness, and type of surfaces to be bonded. For example SEM 39337 will bond SMC to SMC or SMC to steel. 39747 is another SEM adhisive that will work for you, bonds all surface types and gives about an hour of working time.

Barney 5 said:

Thanks for the info! SMYDA, the car is a 79. I'm not sure what the difference is between SMC and GRP? I was under the impression that SMC was the plastic type material used on the 83 on up models?

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First.....there are no stupid questions:thumbsup:

GRP is what everyone thinks of when they think about fiberglass.
Typically what boats are made of. It has a rough texture on the back side.
'53 thru '72 Corvettes were made of GRP, with the exception of a few panels
like hoods in later years........from what I understand.

In '73 SMC was used through out the car. There seams to be a difference
between the SMC used on the C3s and what is used on the C4 and up cars.
SMC can be identified by its marble like appearance and the fact that it is
slick on both sides of the panel.

As I had stated in my introduction thread, "there's more than one way to skin a cat."
The products mentioned so far are all good products. It comes down to personal
choice in most cases. The 3M product is what is use the most in the Body
Shops in my area. We use a lot of Evercoat products as well but I do not
have experience with their panel bonding agents.

Here's a pic of the product I mentioned in the last post.
As mentioned by others, it may not be the most cost effective for the
Do-it-yourselfer. But I can vouch for the integrity of the product. And it
can also be used for a number of purposes besides SMC-glass repair.
Cartridges come with two mixing tips, extras can be purchased.
It is sandable and will feather nicely (though it is not the easiest stuff to sand )
It can be topcoated with most any polyester filler.


Here are two different dispensing guns: The top one is my personal gun I
bought several years ago. I honestly don't remember how much but I think
it was in the $50.00 range. The lower gun is one of the $250+ types.
My personal gun works far better than the expensive one.


The advantage to going this route is it is easier to apply the bonding agent
in hard to reach areas. One can do neat and cleaner work. Also 3M makes
other products like seam sealers and automotive foams that are applied the
same way with the dispensing gun.

Like I stated earlier it comes down to personal preference and budget.
I hope this helped answered your question regarding 3M.:cheers:

If you find another product that gets the same job done....................
and to your satisfaction...........that's all that matters :thumbsup: