Scarffed my sides

Outboard designs up to 14'

Moderator: ttownshaw

Post Reply
Posts: 1378
Joined: Tue May 05, 2009 12:18 pm
Location: Raleigh, North Carolina

Scarffed my sides

Post by gdcarpenter » Wed Apr 06, 2011 4:55 pm

Slow as molasses, but finally making some progress. Darn job keeps gettin in the way. Old company had me out of town 3 out of 5 days. Start new job Monday, 1/10th the commute so should have some evening time boat work coming up. Been almost 10 months now.

Anyways, decided to repurpose the remains of my old Ryobi table saw. It died valiantly trying to rip 8:4 white oak. I scavenged the rails and cross cut sled, made a ton of modifications and voila, a jury rigged scarffing machine. The holes in the 3/4 ply at the 'business' end of the set up are above a 'box' mounted to the underside into which the Fein vacuum goes, the suction really helps hold the marine ply for more accurate cuts.

Despite advise otherwise I went with a 'shouldered' or 'nibbed' scarf joint, the 'shoulder' is about .012" deep and it still leaves me with a fat 2 3/8" of scarf width, which together with 24" wide panels, gives me some 60 square inches of contact area. I may run a strip of fiberglass over the joint on the inside, and the outside will be glassed in any event.

Grateful for having found the instructions for the scarf gluing contraption that I followed more or less, and thankful for having the perfect workbench to work on. In one photo I think you can see how the top clamping board is like a rocking chair on the underside, worked quite well.

Now putting a few coats of epoxy on the inside of the assembled 16' pane, seems much easier to 'encapsulate' the inside now rather than later.
This is my first, last and only boat build.

Posts: 1412
Joined: Wed Feb 17, 2010 5:42 pm
Location: Sunshine Coast, Queensland, Australia. Building Gentry.

Re: Scarffed my sides

Post by Trackhappy » Wed Apr 06, 2011 7:33 pm

What a neat workshop!!!!
By the time I have built a boat, I'll be ready to build a boat....

User avatar
Posts: 1291
Joined: Sun Dec 07, 2008 3:31 pm
Location: Cullman AL

Re: Scarffed my sides

Post by thudpucker » Wed Apr 06, 2011 8:05 pm

Trackhappy wrote:What a neat workshop!!!!
Yeah, obviously nothing happens in it :lol: Or it'd look like my barn.

Years ago I made a Drift boat and had to make Scarf's on the two sides. After a couple tries on those sides, I decided to butt joint the bottom and use a piece of Plywood to bolster the Butt joint.

I had to make a "machine?" to do my scarfing.
I screwed the Side down to a bench I made just for the purpose.
Then I made two rails, crossways to the sides.
Then I made a Carriage that would ride back and forth on the rails, and put the Skill Saw into that carriage.
Adjusted the Height and started sawing the Side plywood down.
The carriage at an angle kept my scarf angle true.

Soon I got tired of doing 20" of scarf, 1/8" at a time.
I bought a Dado Blade to make my Scarf cuts 3/4" at a time.
That was mo-much bettah!
Still I had little bumps that kept the two Scarf joints from sitting face to face.
I skidded those little bumps off with a Belt sander. Still it wasn't good.

So....I put a layer of Fiberglass cloth between the two and glassed it in.
That held. But it was bulgy looking.
I decided that was waaaaayyyyy too much trouble for two sides.
I think from now on (Mr Jon) project will be Butt Joints with a Backing sheet.
At some point in time, while I'm still able, I want to use the boat in the water. Scarfing takes too much time.

Posts: 308
Joined: Sun Sep 17, 2006 3:21 pm
Location: Canada, Southern Ontario

Re: Scarffed my sides

Post by Scott » Sun May 01, 2011 7:19 am

What is scarfing?

A flash of lightning with a simultaneous crash of thunder.

An ignition system of early Mercury outboards that not only is a nightmare to diagnose but also improves a marine mechanics competency.

Post Reply

Return to “Small outboards”