Jim__H

Hi all,
I did not know this Paint and Body section existed, guess I have been posting in the wrong place...here is my post from yesterday, looking for some adhesive advice:

Some of you may have seen my thread on replacing the front fender on my '77. From what I can tell, the best two options for the adhesive are the 3M 8115 and Evercoat 994 SMC Panel adhesive. If I can borrow an applicator gun from a shop that did some work for me previously I'll probably go with the 3M but if I can't do that is the 994 a good alternative?

And if anyone has ever worked with the 994, what is the working time? The 3M literature claims an "extended work time" for the 8115 which is great, I can't find anything on the 994.

Thanks!

DUB

I have used the EVERCOAT 994 SMC Panel Adhesive.

Personally/Professionally 'speaking'. I do not use any two part adhesives that come out of a caulking tube on any panel that has an exposed bonding strip that will need to be filled in.

I DO use the structural adhesives in the caulking tubes on panels where this adhesive is UNDER the panel and NOT exposed or having to be covered with a body filler.

I KNOW many people have used a structural adhesive and had no effects ( so they say)...but seeing how I do this type of work and have to warranty my work....I have mastered a process in bonding panels on WAY before these two part epoxy/urethane structural adhesives became a common product used in current auto manufacturing.

YOU can control the working time of the 994 IF you perform some testing...because YOU add the hardener to it. SO...there may be a chance that you may waste some adhesive in performing your tests. And when you are performing your tests...you CAN NOT have a large blob of the adhesive and time it to find how long it takes it to gel and no longer be viscous like peanut butter and be able to go back into itself.

The reason you can not mix it up and leave it in a large blob is because it will build up internal heat from the chemical reaction and give you a false time. IF you test your mix...you need to spread it out and have it be as thick as you somewhat can figure it will be when you put the panel on. SO including the induction period that is required as you will read on the can...and you time yourself on how quickly you can apply the fender and get it set...that will be the time that you need to make sure the 994 is still viscous.

OR...you can use the 3M product if you choose and deal with what may happen in the seam area if it is exposed and any solvents contact it ...like when priming.

One thing YOU NEED TO DO...and it DOES MATTER...and that is contact the vendor you got this fender from and see if you can contact the manufacturer. The reason being...and I 'kinda' have to believe it....even though it has not happened to me... there was a forum member who tried the 994 on a new SMC panel from Ecklers ( I believe) and he told me that he could pull the panel right off ...'clean as a whistle'...and had to use the two part structural adhesive. That DOES NOT make and sense to me....and I have to trust that the prep was performed correctly.

I still use the 994 with no problems.

DUB

Jim__H

Dub thanks much for this info, very helpful especially the advice on figuring the working time. The fender is not new, it's off a '79 and in good shape, it is actually a half clip so no external seam filling. I will need to splice the joints above and below the headlight door and a small spot near the windshield.

I am playing phone tag with a local Evercoat rep, I'll post whatever advice he gives me.

Couple of other questions for you if you don't mind:

The fenders fits great but I do have some gaps (3/8 - 7/16") from the bonding strip surface to the inside of the fender. I was thinking of firring that out with some mild sheet steel formed into an angle and screwed into the vertical side of the bonding strip. Is there a better way to do that? I'll be asking the rep if the 994 is good for a steel/SMC interface.

Also I can just barely see the ghost of the existing bonding strip on the outside of the fender, I guess this is common. I am thinking the best way to fix that is to grind it down along the length of the fender?

Thanks again,
Jim

DUB

Just keep in mind I have to see what you see...so PLEASE make sure your photos can do that.... and they do not all have to be so close up that I can see the molecular structure of the SMC. Close-up photos are fine...but I also need one further away so I can get a perspective of where the issue is located....which CAN make a difference in some repairs.

DUB

Jim__H

Dub, that sounds great. But it won't be until this weekend, I just left for a business trip today and won't be home until Thursday night. Here is a photo of the fender that just happens to be on my computer just to give you an idea of what I have.

Jim

Jim__H

Jim[/QUOTE]

I spoke with the Evercoat rep and he said the 994 would work but then he said at temperatures in the 70s or 80s that would only give me a 5 minute working time. He suggested their 6045 which is supposed to be identical to the 3M 8115. He also said that he could lend me an applicator gun. But as we kept talking, he suggested Evercoat 100815 which is dispensed by a standard caulking gun. This product looks perfect, thoughts?

DUB

Jim,

If you are planning on using the part you showed a photo of....the 994 can be used at the cowl area...BUT...where you plan on splicing this used part into the original part...that will require a bit of lamination and where the section above between the headlight opening and the hood WILL require the two part adhesive in a caulking tube.

I do not know where you intend on putting this used part to the original part....and WHERE you choose to cut and splice it DOES have a great effect on how you have to bond them back together.

DUB

Jim__H

Dub, I think it will be a lot clearer when I get home and get some photos posted. But are you familiar with the 100815? It's a one-to-one epoxy and it looks like it will work for the internal bonding strips and the steel U channel above the headlight. Here is the cut sheet:

http://tinyurl.com/zo5jxy8

As for splicing the outside mating surfaces I have some Evercoat 864 and fiberglass mat for that.

Jim

DUB

I am very well aware of these type of cartridge adhesives. I have been doing body work on Corvettes for well over 30 years and was doing work on them before these two part cartridge adhesives became a common thing.

I will wait to see what you actually have going on and where you plan to splice it.

I do know that I would not use the SMC resin from EVERCOAT...I have had NOTHING but problems out of it...and have not used it in over a decade. I use another brand of resin.

DUB

Jim__H

Ok here are some photos. First with the fender dry fitted to the car, here is the area above the headlight door. I have not beveled the edges yet.

Jim__H

Next the area below the headlight door

Jim__H

Next the right rear corner of the engine compartment

Jim__H

Now with the fender off some photos of the internal bonding strips

Jim__H

The bonding areas at the front of the car

Jim__H

I mentioned before that there are some areas where there is a gap of between 3/8 and 1/2" between the bonding strip and fender. I am thinking that I could fir out the bonding strip by making up an angle piece out of mild sheet steel and attaching it to the bonding strip. Here is what that would look like, is this a good fix for that? If not what would you recommend?

Jim__H

So that's all of them. If you need to see something else let me know. I found out yesterday that I do not have access to a 3M applicator gun but I can borrow an Evercoat gun. The Evercoat sales rep recommended their 6045, or he also said the 100815 (which only requires a caulking gun) would work as well. Is one better than the other? The rep said they were pretty much the same.

Dub, I am surprised to hear you say you don't like the Evercoat resins but you certainly have my attention and if there is one you like better what would that be? Hopefully I can return the 864 to O'Reilly's for a refund.

Thanks again for advice Dub.
Jim

DUB

Jim,
Just to clarify...I did not write that I did not like EVERCOAT resins...just THAT specific resin. I mentioned it specifically. (SMC resin) Just so we are clear on that. I do LOVE many of the EVERCOAT products. That specific one...I would not ever try again.

If my opinion here means 'jack squat'...those metal flanges need to go. I have dealt with gaps that wide and it is no problem getting the panel to bond on ONCE you know you have that amount of gap. It just takes an extra step or two.

Knowing that you have already cut the body panels to get this used part to fit...the splice areas are going to be FUN to get right and NOT crack back on you.

I still stand firm on using the 994 at the cowl and using it to install a bonding strip on the section of the part where the wide support brace is for your headlights. This bonding strip would fit inside the support beam. Then using a two part adhesive to bond the metal of the headlight support beam to part you are installing.

And I would also use it at the very front where the retainer is for your bumper so it is bonded to it along with the required pop rivets.

Then that is when I would spend the time to carefully laminate these seams so they do not come back and haunt you.

I would not have cut it there even thought it seems to be the best spot...in my opinion. BUT that is also not seeing what the damage looked like before you cut on it. Where these slices are are located will require some careful laminating. Because a crack can start from an edge.

DUB

Jim__H

Just to clarify...I did not write that I did not like EVERCOAT resins...just THAT specific resin. I mentioned it specifically. (SMC resin) Just so we are clear on that. I do LOVE many of the EVERCOAT products. That specific one...I would not ever try again.

So which resin would you recommend for splicing at the first three photo areas? I am not committed to the 864, if there is something that is better I'll go with it even if I have to eat the 50 bucks.

If my opinion here means 'jack squat'...those metal flanges need to go. I have dealt with gaps that wide and it is no problem getting the panel to bond on ONCE you know you have that amount of gap. It just takes an extra step or two.

Ok, that is why I'm asking. So what do you do in this case, build up the surface? If so how, adding layers of adhesive? Filler?

Knowing that you have already cut the body panels to get this used part to fit...the splice areas are going to be FUN to get right and NOT crack back on you.
The fender was already cut there. The fender that came off the car was not the original, it had been poorly fitted and the area to the left of the headlight opening was all bondo. That splice was pretty much in the same spot. I don't know what else I could have done, guess I am stuck with it.

I still stand firm on using the 994 at the cowl and using it to install a bonding strip on the section of the part where the wide support brace is for your headlights. This bonding strip would fit inside the support beam. Then using a two part adhesive to bond the metal of the headlight support beam to part you are installing.

Just to make sure I understand you, you're talking about the first photo and installing a bonding strip to bridge the splice areas above the wide U-shaped support piece?

And I would also use it at the very front where the retainer is for your bumper so it is bonded to it along with the required pop rivets.

Ok

Then that is when I would spend the time to carefully laminate these seams so they do not come back and haunt you.

Ok

I would not have cut it there even thought it seems to be the best spot...in my opinion. BUT that is also not seeing what the damage looked like before you cut on it. Where these slices are are located will require some careful laminating. Because a crack can start from an edge.

I understand that, and I will be very careful not to introduce any right angle stress points

So is the 100815 ok for the bonding seams below the A-pillar, door and the side scoop area? It seems like it is the easiest one for me to get and use. To save a few bucks could I use it at the cowl in place of the 994?

Thanks...

DUB

You are SAVING so much money dong this yourself...that spending money on the products that I would spend them on is up to you.

DUB

Jim__H

Dub, that is true although this part of the project was not supposed to be a big deal. A couple of cracks in the fender, I had no idea there was so much previous repair and bondo in there. I am way over budget on this car but I blame the 700R4 from Bowtie Overdrives and the Vintage Air unit for that.

But now I think I have a good plan for getting this fender installed properly. I'll pick up some 994 and the West product and send the 864 back where it came from. I really appreciate you taking the time to give me your sage advice.

Jim