Inter specie joins...

[CharlieCobra]

What do ya think? Can ya join Black Locust with White Oak? If so, what glue?:confused:

[Thorne]

Not in Utah. :D

Thickened epoxy should do the trick. If concerned about gluing WO you can try one of the epoxies formulated for 'oily woods' == Smith & Co. and others have come up with products for this.
http://www.glueoakandteak.com/

You may want to test first, as many here don't think using anything but resorcinol glue on WO is appropriate for larger boats.
http://www.jamestowndistributors.com/userportal/show_product.do?pid=2060

[ssor]

I think they are stronger than any of the glues.

[rob]

I think it would depend on how much cross grain surface area you are talking about. They have pretty different moisture stability..a wide surface could easily warp or tear itself apart

[Bob Smalser]

Depends on what you're trying to do. Edge grain to edge grain using a compatible glue shouldn't pose any problems.

These kitchen hutch drawer sides are Eastern Red Cedar edgejoined to Red Oak runners for wear using UF resin glue, with RO drawer fronts, cedar backs and cedar crossgrain panel bottoms. They have exhibited no problems at all in 25 years of daily use.

http://pic20.picturetrail.com/VOL12/1104763/2594265/36624721.jpg

But neither WO nor Black Locust is an exceptionally stable wood.....you can expect more problems with a large lamination of face grain to face grain in either species glued singly, let alone gluing them together.

http://pic20.picturetrail.com/VOL12/1104763/2594265/40988956.jpg

[ssor]

Would scuffing the mating surfaces with 50 grit sand paper and using PL Premium and clamps be any better than other bonding methods?

[CharlieCobra]

This would be end grain to end grain. I'm scarphing in a section of the clamp and like the rot resistance of Black Locust and it's strength, especially at the chainplate areas. The scarphs will facing down so any pulling up by the chainplates will push the joins together. How long should the cuts be to avoid possible warping, especially since this is curved slightly perpendicular to the cut? I could use a couple of bolts there if it'd help. The dimensions are 3"X6"X12' for this piece with bolts laterally every 10" and every 10" vertically.

[ssor]

Charlie, They used to make jonts like that with an interlocking overlap.

[ssor]

Found a link:
http://www.salisburywoodworking.com/index.php#mi=2&pt=1&pi=10000&s=21&p=2&a=0&at=0

[Bob Smalser]

This would be end grain to end grain. I'm scarphing in a section of the clamp and like the rot resistance of Black Locust and it's strength, especially at the chainplate areas. The scarphs will facing down so any pulling up by the chainplates will push the joins together. How long should the cuts be to avoid possible warping, especially since this is curved slightly perpendicular to the cut? I could use a couple of bolts there if it'd help. The dimensions are 3"X6"X12' for this piece with bolts laterally every 10" and every 10" vertically.

The differences between WO and BL are negligible for your purpose. Both are strong, heavy structural woods and both are rot resistant. I can't see that complicating your gluing problem gains anything.

If the oak clamp is original, you need to insure it is under the 15% MC limit required by resorcinol, which is the only glue I'd consider for such a large structural member. Wrap an electric blanket around the joint after glueup to insure it remains above 70 degrees F for around 12 hours.

I don't understand your scarf orientation comment. If you are scarfing and bending in new wood to an existing clamp that requires a lot of clamping pressure, there aren't many options.

[CharlieCobra]

I have the BL, I don't have the funds currently for the WO, hence the thread. I figured to bend the piece on a table with holding pegs before attempting the glue up. This is going to be a complicated join.... If resourcinal need a 15% moisture level, the BL is out then. What I have is air dried and higher in MC than that. The bend is probably 12-16" over the 12' span so I'll have to steam it.

I suppose I could use a sawn piece.... Terrible waste of wood though and would require a honkin' big piece...

[paladin]

Darn, Charlie...I haven't had any problems with inter specie joins.....or izzit inter race joins within the species......?

[Bob Smalser]

I have the BL, I don't have the funds currently for the WO, hence the thread. I figured to bend the piece on a table with holding pegs before attempting the glue up. This is going to be a complicated join.... If resourcinal need a 15% moisture level, the BL is out then. What I have is air dried and higher in MC than that. The bend is probably 12-16" over the 12' span so I'll have to steam it.



I don't think gluing will work in this case. While they are similar weights and strengths, locust is significantly more stable than oak and while locust takes glue well, oak doesn't. Plus you have wet wood and stock too thick to dry easily.

But as this is a clamp that only supports a short deck (?), and is fastened to the frames every 10", bolting or keying rather than gluing the scarfs together and positioning them atop and fastening them to frames may be sufficient. That's how it was done before reliable marine glues came along.

Either way, I think your scarfs will have to be oriented to the bends required, not to chainplate stresses.

http://pic20.picturetrail.com/VOL12/1104763/2595357/70507451.jpg