clearance for removeable parts

[davidpm]

What kind of clearance is best for movable parts like a door against a bulkhead. If each piece is going to get 3 coats of epoxy plus several coats of varnish and or paint you donn't want them to fit too tight.
I was thinking that a piece of 80 grit sandpaper would be a good thickness test.
So how may layers of 80 grit paper should fit in a joint so you know you have enough clearance?

I'll bet you guys who have built multiple boats know exactly how much room to give it.

[BenthosCritter]

I would just go ahead and put the on something sacrificial and then cut it in half to see for yourself. My gut feeling? 3/32 of an inch....perhaps even 1/8 if you really plaster it on.

[feetup]

I'm not sure if I understand your question. Do you mean a door in a frame or jamb? Is there a possibility of twist or flex in the bulkhead?
My experience with such things would suggest that lots of clearance is good. The tendency is to want a machinist's fit, but even sealed with epoxy wood swells and moves with the seasons, and there is nothing worse than a door or the like sticking because it swelled. I would say a WORKING clearance of 1/8" is good. Three coats of thickened epoxy is going to be at least 0.090", most likely more.

Feetup

[davidpm]

Originally Posted by feetup

I'm not sure if I understand your question. Do you mean a door in a frame or jamb? Is there a possibility of twist or flex in the bulkhead?
My experience with such things would suggest that lots of clearance is good. The tendency is to want a machinist's fit, but even sealed with epoxy wood swells and moves with the seasons, and there is nothing worse than a door or the like sticking because it swelled. I would say a WORKING clearance of 1/8" is good. Three coats of thickened epoxy is going to be at least 0.090", most likely more.

Feetup

Yes exactly. Any place you have a panel that has to fit inside something and the panel and the something has to have a finish on it, door in frame, flush drawer, access board on floor or removable panel in a seat.
I was thinking 1/8" raw wood to raw wood would be a lot. But with three coats of thin (not thickened) epoxy encapsulation plus a few coats of varnish or a coat of primer and a couple coats of paint plus possible swelling I'm not so sure.

[feetup]

Davidpm;

If you are sealing a raw edge on your panels I would thicken the epoxy some with colloidal silica (cabosil) help it fill the grain, and to give it some more tensile strength to resist cracking as the end grain swells , which it will even though encapsulated. There is almost always a way for atmospheric moisture to gain entrance to the interior of the wood such as screw holes for hinges and latches etc. or finish damage from sharp objects etc. If you have a finished edge with solid wood nosing or such it is still a good idea to thicken the epoxy a little bit for strength, though not so much you lose clarity and muddy up the grain.
Either way I can't imagine that you will get more than 1/16" build up on the edges, so if you allow 3/16" all around and don't achieve a 1/16 build up you will still have less than 3/16" gap which is not objectionable to the eye, and let's face it, the more the better for utility.
Benthoscritter ir right, if you do up a test piece using the procedure you intend to use you will know for sure. Perhaps you can set that up for whenever you have some epoxy mixed up for other tasks so as not have to mix three tiny batches as a test.

Feetup