Hello, and please Help

[rjp103]

Hi everybody, I'm new to this fine forum, but have been
an amateur cabinetmaker for more years than I care to remember.
Now here is the problem:
I want to laminate a 1/64" mahogany veneer to the curved lazaret
(dog house roof)of my sailboat. The radius of arc is 60' The dimension is 36" X 46" The under lament is teak plywood, the surface of which is shot. We are looking at a salt water environment.

Now my question:

How much pressure in psi do I need to laminate using epoxy? Remember
36X46 = 1656 square inches, so if you say 1 psi, those sandbags will crush the roof.

If I need more, how can I get UNIFORM pressure on a curved surface?

Thanks in advance for any consideration.

Dick

[dbriski]

For clarification, your not removing the roof? So a vacuum bag situation wouldn't work.

[mrohde]

I'm having trouble picturing this. I've always called the under-seat storage in the cockpit a lazerette. The doghouse is what I've called the top of the cabin. Neither of those on my boat have any wood, so my picture is incomplete.

Got a picture? Or what type of boat is it? It would help if we could see what you're doing.

[rrich]

Dick,
Maybe epoxy is not the answer. Have you considered contact cement?

[TDHofstetter]

Welcome to the forum, Dick!

I think possibly is one of those terminology thingies that gets between native English speakers and native English speakers. :) Witness bonnets and hoods and boots and roofs.

For laminating with epoxy... you really don't need squat for pressure. What you need is a means of evenly distributing the epoxy in as even and THIN a layer as possible, a means of wetting both surfaces completely with the epoxy, and a means of getting all the air bubbles out from between the layers as you laminate. The pressure is secondary as long as you can accomplish those three things... once you have the layers stuck together nicely, the veneer won't try to lift back up.

I'd suggest rolling the veneer on and using either a veneer hammer or a laminate roller to get the bubbles worked out to he edges.

-- Tim --


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[rjp103]

rrich
Thanks r,
I am told by experienced sailors that a salt environment
is death on contact cement. In a blow, the coach roof gets
awash in spray.
Tim,
Thanks, that makes a lot of sense.
I think that the next step is to determine how to get the epoxy
tacky enough so it would not lift; like areas around screw holes
etc. and still roll out a uniformly thick layer.

Thanks again Tim,

Dick

[Sawduster]

If the surface of the underlayment is "shot", but the ply is, over-all serviceable, I might be inclined to bed the surface with a layer of fiberglass before applying the veneer, then sand the surface as smooth as I could get it. That veneer is gonna telegraph most any sort of change in surface beneath it. It is gonna be tricky to get the epoxy to tack and have time to roll out air bubbles as epoxy goes real quick from being tacky to stiffening.

[JBark]

The typical boatbuilding epoxy has a pretty long drying time so you have plenty of time to work and clamp you piece. Not knowing what this looks like I would try a series of band clamps, possibly adding some cross pieces of wood (perpendicular the bands) to distribute the pressure. This could be expensive so Harbor Freight might be a good source for a cheap "disposable" clamp.

Epoxy being a good gap filler will help, as you will not need the best of mating the two surfaces. Another method of distributing clamp pressure might be a couple of layers of bendable ply or 1/4" between the bands and your veneer. If you have a table saw you can kerf ply yourself to make it bend.

John

[FrankC]

Can you use several canvas webs with weights attached to them slung over the roof to clamp the veneer down?

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