using 3m panel bond as seam sealer in trunk area

[72restocuda]

I'm sure this has been asked before but I haven't found it.  Using panel bond between panels in the trunk after welding the trunk floor extensions and also around the rear wheel wells seams to the trunk floor to increase strength and of course seal the seams.  Any thoughts. Thanks

[Cuda Cody]

3M makes some good stuff and you might be okay, but I think the reason to use seam sealer is to have some flex and a water tight joint.  The super strong 3M panel bond might crack or separate on one side and could be a leaky spot?  Then rust might form faster if water or condensation gets in there.

[72restocuda]

good point, hopefully someone on this site has tried this and either failed or been happy with the results, no reason you couldn't use both, a thing layer of each to get the best results

[jimynick]

I'm one guy who tried it and found it works great. I did use actual seam sealer as well. I sealed every seam where two pieces of metal came together on the car, because in tearing it apart, I found rust in every one of those places. The 3M products are good, if expensive, but how far would a couple of hundred bucks go toward rust repair? Mind which bond you choose and ask the supplier or go to 3M's site to get a leg up on your choice. Some of them actually have micro balls in them to preserve the micro gap required for proper cure and strength. Mind the varying work/cure times as well. Do it, you shouldn't be disappointed. 

[RUNCHARGER]

Price is the only downside but it isn't enough not to use it. I love using it to secure/seal 4 speed trans humps too.

[MoparLeo]

An old bit of advice about product prices , " The quality is remembered long after the price is forgotten..."

[71chally]

Are you all welding through/around it?

[jimynick]

We welded through the bond in the cowl/firewall panels to make them one piece when installing, but generally, no. 

[71chally]

We welded through the bond in the cowl/firewall panels to make them one piece when installing, but generally, no. 

I've been considering spotting and panel bonding the lower section of upper cowl panel. Did you try that?

[jimynick]

If you're meaning the upr cowl mounted on top of the firewall, then yes. It also gives you a sealed inner seam, which otherwise is a bitch to achieve. 

[torredcuda]

I didn`t see anything about flexibilty on thier data sheets but being an adhesive that bonds metal panels that see both hot and cold temperatures as well as road bumps and vibrations I would guess it would be OK and not crack as long as it wasn`t too thick, it might even add some strength. As with anything prep is important.

[71chally]

If you're meaning the upr cowl mounted on top of the firewall, then yes. It also gives you a sealed inner seam, which otherwise is a bitch to achieve. 

Thanks any pics? I've been going and back on forth on this and was leaning towards plug welding it because I was concerned about strength of the panel bond in a assumingly structural application.

[72restocuda]

well I'm convinced to use 3m panel bond, then epoxy primer then brush on seam sealer from Eastwood after plug welding pretty much all the panels

[jimynick]

You shouldn't need seam sealer if you do it right in the first place, but if it makes you feel better, go for it. 

[72restocuda]

Thanks for the helpful hints, must be great to be perfect