Attaching side trim

[shortgmanp]

My dad and I were wondering if it would be ok to put butyl tape behind the oak side trim and attach it to the body, then remove the excess tape. Both the body and trim will have about 3 coats of varnish before this trim would be attached. Also the trim will be treated with cpes on the back before it is varnished. Then the whole tear would be sealed after the trim is installed. I just want to make sure water cannot sneak in behind the trim. Any ideas would be appreciated. Thank You Greg P

[48Rob]

Greg,

It won't hurt anything to use putty behind the trim...but, if you have the wood sealed well enough, I would be more concerned with moisture getting into the breaks in the finish you'll create when attaching the wood.

The method I use is; Install the screws that hold the trim, then remove the screws and trim.
Next I use a small countersink/bevel bit to create a small pocket on the backside of the trim in/around the screwhole.
I also use the deburring bit to just lightly touch the hole in the body, where the screw has raised the wood slightly.
Then I apply a dab of sealer in the recess just created, and inject sealer in the hole in the body.
I now reinstall the screws, and glue a plug in the hole in the face of the trim.

If you're going to leave the screwheads exposed, the same method will work as long as you also inject sealer into the hole in the face of the trim, so that when the screw is installed, a little squeezes out under the screwhead.
No moisture can get in now.

Putty tape is good stuff, but can dry out over time.
If you have the ability to remove screws and wood trim down the road, it can be replaced, but for a wood project that can't be taken apart easily, it isn't the best choice.

Unless the trim is glued to the body, water WILL sneak in behind the trim.
It won't hurt anything as long as the trim, and body wood are well sealed.
If it were mine, I'd add a couple more coats of varnish, at least the backside of the trim, and the body where you'll NEVER be able to add any later...3 coats isn't bad, but 6 is much better insurance...

Rob

[Steve_Cox]

I tend to agree with Rob, eventually water will intrude upon trim that isn't permanently attached. Varnish will fail if wet and occluded by putty. I put trim on with epoxy after coating the surface under the trim with epoxy. Some trim is just epoxied, while in other places I used counter sunk screws and wood plugs to hold it in place while the epoxy cured.