A little input please

[Jay Jolliffe]

I have to make a seat on a deck that will be made out of 2x10 Ipe ....They would like it to crown so the water runs off. How would you make a consistent crown for 9' ?

[Kent A Bathurst]

Crown which direction? over the 9' length? or front-to back across the width?

What is that dimension, BTW - one 2x10 for the seat? Two of them?

[Peter Quinn]

Do they want it higher in the middle of a 9' span? I'd make the legs or supports at the ends shorter than those in the middle , and If the piece or pieces of IPE you use happen to have a a crown that works in your favor, so much the better! If they don't, you should be able to get it to bend the 1/4" or so necessary over that span that would be necessary to shed water. Not sure it has to be so crowned that it will be highly noticeable so consistent or not it wont show. I'm thinking a bench that long needs 5 supports or divisions, so you could make the middle one the highest and step them down to the outer edge. Or resaw piles of IPE into veneer, glue lam it with epoxy over a curved bending form and sell the bench seat for $9500. They have some stainless legs on etsy,, like a welded upside down U shape, could maybe do something like that if the design supports it, and just modify the heights

[Jim Dwight]

Bark side down on flatsawn lumber will tend to result in a convex surface on top, a rounded surface. On species prone to splinter, however, it can also increase that. I don't know if splintering is an issue with ipe or not. But a more foolproof way to avoid standing water would be to slant the seat a little back. Slanting it forward would shed water but also be uncomfortable. Slanting it back slightly is comfortable and will help shed water. You could still go bark side down if you want.

[Jay Jolliffe]

I guess I didn't explain it right. The seat that is there is a 2x10 of spruce on a short wall maybe 16-18" tall that is made from 2x8's, shingled on both sides. I have to replace the rotted spruce that was the cap for the wall with ipe 2x10. The crown has to be across & not the length of the 2x10.I thought if I use double sided tape & taped a 1/4" strip along the bottom edge the length if the piece I have to do & clamp a 1x3 of something to the bed of my planer to use as a side stop to keep it in the same place the length of the board....any problem in doing this ?......Hope that's a little clearer....

[Dave Zellers]

A handheld power planer would be the best approach I think.

[Kent A Bathurst]

OK - makes sense now - I was a bit lost before.

Yeah your shimmed planer trick would work, or Dave's power hand planer would work - - or --- split the 2 x 10 in half, small shims under the center, power hand planer or belt sander with serious grit to fair the curve.

[Peter Quinn]

I use a planet sled for those, much as you described. Usually it's a piece of 3/4" melamine or pre fin ply for a bed board, a hook at the leading edge to grab the planet table, a strip on the low end of plywood or solid scraps to direct the travel path, and a strip on the high end tacked down with brads to set the travel. I have gotten fancy before and ripped the strip to a known angle, say 5 degrees, so you have more bearing surface. I usually lay out the pattern on the end of a test piece, pull the angle from that, rip my little riser strip, lay it out manually on the bed board. I actually made all the hand rails for my own house's old front porch the same way. Of course on an open grained wood over a short distance you need a hell of a bevel to actually get water to run, the IPE will never rot so it's almost irrelevant, spruce is mold food and would t last anyway, but it's a cool detail none the less.

[Cody Colston]

I would rip two bevels on each side with the table saw and then use a hand plane to clean up the ridges...or even an angle grinder with a 40 grit flap sander.

[Mike Schuch]

You are going to try to bend Ipe across the grain on a 10" wide piece? That does not sound very promising to me. Maybe a softer wood but not Ipe. Even if you steamed it first I just don't see it happening.

I would use narrower boards. Cut slight angles on the sides. Glue them up. Then smooth with a planer.

What ever you end up doing please let us know what direction you decide to go and how it works out for you. It is a very interesting problem to solve!

[Peter Quinn]

I would rip two bevels on each side with the table saw and then use a hand plane to clean up the ridges...or even an angle grinder with a 40 grit flap sander.


Handplane.....IPE.....good luck.