[geeky2]

hello,

i am sealing the cowl hats on my 68 mustang.

i purchased 3M Brushable Seam Sealer 08656 for this task.

i applied a thin coat of sealer with an acid brush. after the sealer dried - it cracked.


the cowl was primed with epoxy on Saturday 3/10 of last week and i put down the sealer last night (Tuesday 3/13).

attached are two pics. one is a picture of the product that i used. the other pic, shows the cracking in the sealer after being allowed to dry for approximately 5 hours in a garage, at 60 F degrees.

before i put down the sealer, i cleaned the surface with wax and grease remover.

can someone tell me what i am doing wrong and why the seam sealer is cracking?

thank you
mark

[Silentfallen]

did you use some sort of cleaner/degreaser on it before putting the sealer on?

[MARTINSR]

I am thinking the primer sucked up the wax and grease remover and now it's coming up thru the sealer. There is no reason what so ever to wax and grease that fresh epoxy primer for seam sealer. The other problem is that seam sealer is junk, out dated as lacquer primer, pure and simple junk compared to a 2k sealer. After all that work you are doing I HIGHLY recommend you bite the bullet and get some real seam sealer from 2012.

Brian

[geeky2]

yes - i did use a wax and grease remover, then wiped it off.

the product is named pre/klean un1263 - part no: XL91001.

i am a beginner and was not sure if i should prep the surface or not - lesson learned.

i will grind off the epoxy and re-shoot.

someone else suggested that i go with fusor 800EZ for all of my seams.

mark

[MARTINSR]

Originally Posted by geeky2

yes - i did use a wax and grease remover, then wiped it off.

the product is named pre/klean un1263 - part no: XL91001.

i am a beginner and was not sure if i should prep the surface or not - lesson learned.

i will grind off the epoxy and re-shoot.

someone else suggested that i go with fusor 800EZ for all of my seams.

mark

The problem may be that the wax and grease remover simply didn't evaporate and soaked into the epoxy primer.

Try rubbing the epoxy primer with a lacquer thinner soaked rag to see if it softens or comes off on the rag. If it does, then you need to upgrade your epoxy, what that means is it isn't "insoluble" and not fully cured like a quality epoxy would be. You should be able to rub a lacquer thinner soaked rag on it and get no color transfer on the rag.

That Fusor is a good product, and MILES better than that old 3M junk you are using but it is still a 1k and doesn't cure fully. But again, hundred miles better than what you used. http://www.lord.com/products-and-sol...roduct.xml/340

They have a black one, that would make more sense to maybe if you don't want it seen.

Unless that epoxy primer comes off on the rag (and even if it does a little it isn't the end of the world) really easy I wouldn't worry about removing it. The failure was with the sealer not the epoxy.

Brian

[geeky2]

Originally Posted by MARTINSR

The problem may be that the wax and grease remover simply didn't evaporate and soaked into the epoxy primer.

Try rubbing the epoxy primer with a lacquer thinner soaked rag to see if it softens or comes off on the rag. If it does, then you need to upgrade your epoxy, what that means is it isn't "insoluble" and not fully cured like a quality epoxy would be. You should be able to rub a lacquer thinner soaked rag on it and get no color transfer on the rag.

That Fusor is a good product, and MILES better than that old 3M junk you are using but it is still a 1k and doesn't cure fully. But again, hundred miles better than what you used. http://www.lord.com/products-and-sol...roduct.xml/340

They have a black one, that would make more sense to maybe if you don't want it seen.

Unless that epoxy primer comes off on the rag (and even if it does a little it isn't the end of the world) really easy I wouldn't worry about removing it. The failure was with the sealer not the epoxy.

Brian

i'll try the test with the thinner. i don't know if it is lacquer thinner, but all of the materials came from the same company on the same BOM. the thinner that i have is to be used to clean up my gun.

i am picking up the materials tonight and returning the 3M product for a credit. i think i am getting black for the fusor product.

thank you,
mark

[mr4speed]

Have used the Fusor 800EZ it is great for tight seams and really good for the drip rails at the roof. The best stuff I have found for duplicating the correct factory looking brushed on seams ( have tried a lot of them) is Norton brushable seam sealer I believe the pt# is 82746 black and white quart can.

[Sm1nts2escape]

What do you guys recommend for a good non brushed seam sealer? I bought eastwoods seam sealer but don't want to put it on if it is junk?

[123pugsy]

Originally Posted by Sm1nts2escape

What do you guys recommend for a good non brushed seam sealer? I bought eastwoods seam sealer but don't want to put it on if it is junk?

Brian mentioned a 2K seam sealer.
I will only use something like this in the future as I've had seam sealer crack under the paint on my last project.
I googled and found something by Valvoline a couple days ago.

[mitmaks]

I've used that particular seam sealer and I'm not happy with it. It shrinks as it dries and it stinks, pretty potent smell (even though I like strong smells ie body filler, clear coat, etc)

[Lizer]

I started out using that very same stuff, as well as the 3M beige fast n' firm,...the latter most likely because it reminded me of my high school days

They're both junk, and they crack. You aren't doing anything wrong, they just crack.

I am now on to 2k Pliogrip. They make the gun for 3M 2k products, but the pliogrip gun is cheaper. However, both 3M and Pliogrip cartridges work in the Pliogrip gun. I went with them because they're apparently the OEM seam sealer.