Joints in bright-finished plywood

Is it possible to make an "almost" invisible butt-joint
(with butt block) in epoxy-coated and varnished
occume plywood (bright finish)?

Does it need to be scarfed, or will even that not produce
an "almost invisible" joint?

Would adding a layer of light glass cloth help hide the joint
(again, with a varnish coating)?


Thanks

 

The difference in grain will show the joint.

 

Right. So accept the fact that full lengths are not covering the boat. Skillfull use of base colors and grain patterns is a un-learned but very beautiful art on the siding of a boat. In the 1930's, boat plankers were so good at it that solid matched planking looked cheap next to a selected planked hull. Some people love all white luxury yachts.

 

If your joint uses epoxy as an adhesive the joint should be wider then other adhesive types, in fact epoxy relies on a reasonably thick joint area to perform well.

A line will be seen with the best joint and thinnest adhesive. Plywood's wild grain (unless it's sliced, quarter sawn stuff) doesn't help this issue much as grain matching is near imposable. It can be hidden a bit with darker stains and the joint itself can receive a graining treatment. I've done this to match repair sections. You literally paint a matching grain on the joint area, using a 000 radiograph or brush sized as necessary. It's still there, upon close inspection, but doesn't jump out at you, if you put a lot of time into it. This is about the most tedious type of work I know, about like painting a wrist watch face with new numbers and a small logo of some sort. You work under a loop or as I have a magnifier lamp.

Plywood, even the pretty stuff, really looks poor if large panels are finished bright. Planks that aren't too wide can look okay, but the joint count is high on even a small boat with 8 foot panels used for the planking stock.

 

One point you may have missed... you can purchase such ply in 12 foot lengths. I don't know if that is long enough or not but just in case you were not aware of them.

 

I've seen custom 20' lengths of ply, but the price . . .

 

Appreciate the responses.

As pointed out, the cost of shipping long
panels is prohibitive, plus I have a local source
for the 8-footers.

Also, aren't the long panels merely "factory-scarfed"
8-footers? Or are they actually laid-up in the long
sizes?

Certainly bright-finished occume ply doesn't rate
"up there" with genuine wood (for lack of a better
way of phrasing it) but it is a step-up in quality for
me, and I am taking this one step at a time.

Maybe I can figure a way to cover the joint with a
bit of trim of some sort.

 

I just got off the phone with Barbara Hall a major plywood distributor for the big name brands in the north east. Forget larger than AA FIR marine 4'x 10' x 1/4". more mills are dropping their big presses. Lumber Products sells 1/4" x 4'x up to 18'. They have a local carp. do the scarf of 8' then resell them. AA FIR marine is not cheap. Add solid veneer and the epoxy and the sheet is a joke. Might as well go planking. Solid plank and good Bruynzell are about the same. We are boat building dinosaurs. What have the rest of you found out.