Glue two sheets of plywood together side by side. Lap Joint for floor.

Two 1/2" sheets to make 8' long and 90" trimmed down to 53" wide, One thickness. wanting to laminate the two sheets together and trim to 53"wide and have glued seam down the middle. Do I power planer the overlapping edge to a 1/4" thickness and 3" wide then glue and screw together. Making a Lap joint with plywood. Glue or Resin as adhesive to hold sheets together. 1992 Smokercraft Alaskan 13' Thanks, Randy

I don't know what your final use is.

I don't think I would do a lap joint. I think a scarf joint might be easier to get a uniform surface.

The biggest challenge with such a long joint, scarf or lap, is getting a uniform surface.

I think I would use an epoxy adhesive.

Depending on the structure where this is to be used, I think I would also support that joint somehow, particularly if it is to bear weight, like somebody standing on it.

Floor of a Aluminum boat. Vinyl covered. The support for the floor is down the middle the length of the boat. Thanks.

I haven't tried either myself, but have seen others use a scarf joint with good success, using epoxy glue and lots of weight. The post I read, the guy did all kinds of testing, and if I recall correctly, the joint was a little stronger than the adjacent plywood. I believe he used a hand planer, but I can't remember how wide he made the scarf. It was on TheHullTruth somewhere.

I saw this post, and it got me thinking. I have a boat floor to do soon, and if I could scarf boards together successfully, it would save me a lot of wood. If I find that post, I'll put a link up.

Here you go.... Look at post #9, #29, #38 and #45 with pics, to save some reading:

https://www.thehulltruth.com/boating-forum/1125788-simple-skiff.html

thill said:

Here you go.... Look at post #9, #29, #38 and #45 with pics, to save some reading:

https://www.thehulltruth.com/boating-forum/1125788-simple-skiff.html

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Thanks for posting that. Very useful, and not just for boat projects.

On YouTube, the channel "Tips from a Shipwright" covers a lot of useful techniques in a no-BS manner. That guy builds wooden boats from scratch. He plainly shows how he uses power and hand tools to get the job done. He often uses scarf joints and shapes with his portable power planer. I don't have one of those small planers; I have a large stationary machine for that, and a jack plane for handwork. But that shipwright channel has got me considering picking one up.

Why bother with a joint, might be easier to remove if in separate pieces. Some day you will need/ want to get under that floor to get something like you car keys that dropped out of your hand and just happened to find that one small opening and slipped under that nice floor you just installed.....want to know how I know that??

If y

airshot said:

Why bother with a joint, might be easier to remove if in separate pieces. Some day you will need/ want to get under that floor to get something like you car keys that dropped out of your hand and just happened to find that one small opening and slipped under that nice floor you just installed.....want to know how I know that??

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X2. Why not have the floor in 2 or 3 separate pieces with the joint(s) running side-to-side. Wrap the edges with your floor covering. If you ever need to access below the floor you can just pull up the section(s) needed.

If you do want a single piece, I would also do a scarf joint -- mainly because I would enjoy the challenge of doing it along with the result.

The biggest reason is so that you don't waste as much wood. The floor in my one boat is 54" wide, leaving a 42" cutoff. I needed 3 sheets of plywood to do the floor. If I scarfed two of the cutoffs together, I could have done it with 2. It doesn't change how many panels you put down, just how much you can use.

Ray Clark said:

Thanks for posting that. Very useful, and not just for boat projects.

On YouTube, the channel "Tips from a Shipwright" covers a lot of useful techniques in a no-BS manner. That guy builds wooden boats from scratch. He plainly shows how he uses power and hand tools to get the job done. He often uses scarf joints and shapes with his portable power planer. I don't have one of those small planers; I have a large stationary machine for that, and a jack plane for handwork. But that shipwright channel has got me considering picking one up.

Click to expand...

I've watched a number of his videos. He is not far from here, I saw one of his boats from his videos on Craigslist last year.

A planer is a MUST have tool. You don't know how much you needed it until you have one, then you don't know how you got along without one. Kind of like having a screw gun. Sure, your trusty old screwdriver works, but...

Hey Guys, Thanks a lot. This new floor is taking shape Great. Have the wood coated. Now to fit the floor into the boat to see if it has a tight fit to the sides. Then wrap the vinyl staple it on and screw the floor down. After that the Wife would like carpet. That's another story. The vinyl got hot, says the Dog. Thanks for the Tips .