Scarf joints separating

[Mclark1955]

I've got a problem with my new boat. It has been setting covered on the trailer and it looks like the heat from the sun has caused some of the scarf joints to start separating, 3 on one side (the west facing side) and 1 on the other. Any ideas on how to repair these joints? I used TotalBoat2:1 on 8:1 scarfs on white pine.IMG_2680.jpg

[wizbang 13]

joinery is too good
run a bayonet sawzall blade in there. not by hand, with the sawzall. beat the livin crap out of the scarph and the wood.get thickened with 403 epoxy in there. bring the scarphs back down with screws on fender washers.
then stop confusing cabinetmaking with epoxy boatbuilding
...seen it a hundred god damn times
sun is not yer scapegoat
bruce

[Yeadon]

I believe Bruce. That said, I'm curious - what's it like in the joint? Is the epoxy dry and it just let loose because you starved the joint, or is it at all gooey. There's also a chance you got the mix wrong (too).

[Mclark1955]

The joints are dry. I cut them with a hand plane and I had quite a bit of squeeze out.

[wizbang 13]

hand plane = smooth flat wood
when i make an epoxy scarph, i dish it out wirh a disc sander. 36 grit minimum .
it's a hard thing to get ones head around, that bad joinery is good for epoxy
the engineering is still important ..(the length and placement of the scarpf)...epoxy is not magic, that's just the way it works
dishing it out allows one to clamp it so it looks nice , insofar as the ends come together
squeeze out is over rated ..

[Hugh MacD]

What Wiz said. All of my joinery tends to be epoxy ready from the get-go. You guys with real skills are missing a bet

[gypsie]

Once you've pulled the screws with fender washers, you can either fill with epoxy (which will only do the surface), or i would drill out and epoxy in a plug the thickness of the plank.

Squeeze out is overrated
Love it.

[DayTripper]

I've got a problem with my new boat. It has been setting covered on the trailer and it looks like the heat from the sun has caused some of the scarf joints to start separating, 3 on one side (the west facing side) and 1 on the other. Any ideas on how to repair these joints? I used TotalBoat2:1 on 8:1 scarfs on white pine.
(pic deleted to save bandwidth)

Curious. When you epoxied the scarf joints, did you just use unthickened epoxy?

Or did you use the two step procedure?

1. Coat both sides with straight epoxy.
2. Apply thickened epoxy to one side.

[Mclark1955]

I was going to use West System Six10 in my repair but no one has any with no known delivery date from West System. So I guess I’m going to use Thixo.

[wizbang 13]

Is Thixo the Total Boat "ringer" for WEST 610
I never use the pre made stuff, it locks you into one additive and one consistancy.
Be sure to employ a lotta "hydraulics of the wrist" .
Get on it (them)with a 3inch putty knife and pump pump pump the dookie in there . then pump s'more.don't rely on just the pressure of a caulking gun.
Have to checked to see if every scarph on the boat is hinky? cuz uh....yea
I like to say that a little bit of epoxy on a boat is not a good thing.Embrace it or reject it.
Scarphing planks of a carvel boat is kinna daft. Like laminating frames then carvel planking.it's half of a measure .
i'm assuming your boat is carvel and of course could be wrong.

[JimConlin]

In warmer locations, dark colors and epoxy don’t always do well.

[lupussonic]

Scarphing planks of a carvel boat is kinna daft. Like laminating frames then carvel planking.it's half of a measure .

Wha dem a say?