roof drip rail sealer

[RICH MUISE]

Terry had pm'd me asking what I had used for sealing the drip rails.  A bit more detail than asked for as usual, lol, but important stuff:
A few years ago, I repainted my roof because I was having adhesion issues with the seam sealer I had used. After stripping, it was obvious it wasn't the seam sealer, but the epoxy primer under it that was having issues. That was caused by not removing the coating zinc chromate etching leave after prepping the surfaces. That coating prevents the epoxy primer from making adequate adhesion. Before paint, I had already stripped the roof of the first epoxy primer I had sprayed on because I discovered the adhesion problem when trying to feather a repair area. Unfortunatly, before respraying the epoxy primer, I decided to take the chance and just strip it down to the rain gutters and leave the primer/seam sealer/primer in the driprails I had spent so many hours on trying to get right. That was a bad decision....as I said, it led to having to strip them recently and repaint. Not wanting to have the problem again, I asked about the best sealer for this job, and got an excellent response from Pat Fleishman on the using of panel bond adhesive. My god, I couldn't believe the difference, and I strongly recommend anybody doing the driprail sealer thing to go this route.
Here's a link to that thread...... http://57fordsforever.com/smf/index.php?topic=7286.msg62255#msg62255
Terry...I believe it was less than two tubes/kits. I can't remember if one did it. The caulking gun is expensive, but check around, maybe a used one? I was finding 40 dollar differences in pricing. Think I ended up about $65locally for the gun. As your paint supplier if you can return an unused panel bond cartridge. Pat cautioned me about not getting an excess amount in the gutters. I just made sure it curved back up on the outside to cover the seam you can't hardly see on the inside of the driprail lip.

[RICH MUISE]

Unexpectedly easy to apply and work just a wet finger works great for the finishing, but I sculpted some plastic bondo spreaders to a shape like I wanted in the driprails so I could apply pressure to force the sealer into cracks and crevasses. Best part is it sands just like filler when set-up, so final smoothing and blending leads to a neater job than you'll ever get with regular seam sealer. I think Pat mentioned this, but it has an added advantage of having a rust inhibitor........that's understandable considering it's intended original purpose.
Want more reading......I found the link I posted above by typing "3m panel bond" into the search box........came up with a whole page of stuff, including my threads when I was actually doing it.

[terry_208]

What I found was my local paint supplier has loaner caulking guns.  I've used their guns a couple times to seal the floor seams and welds. The problem with that is they loan them out for 7-10 days.  I think they would call and ask someone to return it for a couple hours for me to use.  They know that my stuff is ready to go when I ask for the loaner.  I found that an hour spreading the sealer is a long time.

Thanks Rich.  I had been thinking of nearly filling the drip rails but doing a small bead along the outer edge would be better.  I was going to the page you linked to get the type of sealer to use.  You just made it easier.

My car was media blasted and immediately epoxy primed.  I was told no prep was required, other than a scuffing, on the freshly blasted surface.  I hope that I didn't cause a problem following that advise.  I plan to scuff the primer and prime again before adding the sealer and immediately priming over the sealer.

[RICH MUISE]

I wouldn't "immediately prime over" the sealer/panel bond. Let it dry/cure and do a sanding to smooth, then prime. I took some pics with my iphone last night of what I think is a good shape for the driprail. I'll get them downloaded hopefully (downloading pics from my camera was always so much easier)

[mustang6984]

I cheat when transferring photos from phone to computer...I just send them to my e-mail address...then download them. A little more time...but easier.  Easy is good!

[RICH MUISE]

pics are not too good, but you can see how smooth they ended up without overfilling.

[mustang6984]

Look great Rich. Pics too. Look like glass...probably better than original.

[terry_208]

x2 on the pics and the look.  So panel bond shrinks?  I didn't expect that. 

I'm trying to get to a point that I can have the body shell work done, while its on the rotisserie and easier to reach, before marrying the body and frame.

[RICH MUISE]

Panel bond does not shrink. If you're refering to my comment about letting the different products cure before applying another, it's just a matter of letting each layer/product cure. Applying something over another too soon I would think would slow or stop the outgassing/curing process. Primers shrink when drying, which is why I'd only apply the panel bond over cured primer.
What was your reasoning for respraying the epoxy primer just before applying the panel bond?

[terry_208]

Simply to seal any areas of bare metal caused by the scuffing of the well cured epoxy primer.  The epoxy I use has a 45 min flash time before overcoating and must be sanded after 72 hrs.  Of course, that's at 70 degrees temp.

[RICH MUISE]

Unlike seam sealers, specifically made for that one purpose, panel bond was made to adhere to bare metal or factory primed panels. and it has a rust inhibitor, so I wouldn't be too concerned if there are some small, sanded through areas where the panel bond comes in contact. That's basically the same reason why I use 2 k primers that can be applied over bare metal (many cannot be).  After epoxy, If you have a small area with exposed bare metal, it's not an issue.

[lalessi1]

Kinda off topic but I need to do this on my car... Is there supposed to be openings in the front corners of the drip rail for drainage?

[RICH MUISE]

Not off topic at all. Yes, mine had drain holes. They are probably drilled in after the roof was assembled. That's a low spot on the driprails. However, I let the panel bond close them up. My thought was that is a multi layer area that hole is going through with a definete possibility of a gap between the layers, making for a place for water to seep inside.

[Ford Blue blood]

They are the source of water in the dog leg.  Discovered this when applying rust converter to the drip rails.  Some of it started running into the flat area under the dog leg.  Those holes are now gone!

[terry_208]

Sealing those holes was a question I was considering.  Mind is now made up.  Mine will also be sealed.