Warped Rosewood

[John Reid]

A lot of great input! Thanks so much, all.

I will draft a note to, as you suggest, just let them know.

I also put the pieces back in my humidity box. I’ll wait a bit then try John’s ironing suggestion.

[John Reid]

Oh yeah, the sides were flat and have remained flat.

[Diane Kauffmds]

I keep an old Rowenta iron in my shop for things like this. I think it's caused by low RH combined with uneven thinning. I set the iron to Wool and start with the humped side. You'll feel it relax. When it's about flat, iron the other side. You might have to do it a few times.

Put a thick piece of wood on it and weigh it down.

Rosewood could scorch. It's not a bad idea to put some butcher paper on top and iron on it. It also wouldn't hurt to give it a spritz of water, then iron.

It'll straighten out.

[John Reid]

I thought things were going well, but I’m having some issues.

I tried ironing the pieces, then clamping them between two boards. I think I didn’t do a very good job of the ironing. I took them out of the clamps after a week and they looked better, but clearly not very flat.

So, I clamped them together and jointed them and glued in a back strip. That actually went pretty well, I thought.

Next, I tried thicknessing them with a plane. I tried to not put stress on the joint and got most of the planing done when I heard a little pop. The back strip joint had separated near one end and, though small, the newly formed gap didn’t want to go back together. I didn’t like that, so I decided to separate the halves and start over. While trying to gently separate the halves, the rosewood split about 6” from the other end. I actually got the back strip out nicely, though.

Ok, so I decided to try and not give up – hopefully I get learn something from this.

Next thing I did was glue the little piece of rosewood and shown the picture. That went back on really well.

So, now I’m back with two pieces of curved rosewood. While the one half with the repaired split was curing, I re-ironed the other half and again clamped it between two boards. Today I took it out and it still had a lot of curvature. I ironed the repaired half and put them both back between two boards.

That’s where I am now.

My current thoughts are that 1) I should try ironing again, and 2) Previously I was able to get the halves perfectly flat after having them in my humidity box for a couple days. I’m wondering if I can get them flat that way, can I quickly finish thicknessing them and install the bracing before they dry out?

[TEETERFAN]

I successfully flattened a 10” X 48” X 3/4” piece of red oak using this technique. Lots of info out there on glycerin flattening solutions.

https://www.lumberjocks.com/threads/hom ... on.319822/

[John Reid]

Thanks for the info on flattening solutions. I’ll certainly check that out if/when this happens again.

In the meantime, here’s an update on what I’ve done:

After repairing the cracked piece, I did some more ironing and clamping. I guess my ironing skills just aren’t that good. The ironing helped, but there was still a lot of curvature. So, I was afraid to glue the sides together again and have the same thing happen again. So… I thought if I could thin the sides some before gluing, it should make them more flexible and safer to thin after gluing.

I was able to thin the two pieces separately, but they ended up thinner than the backstrip. I’m not explaining it well, but the bottom line is that after gluing the backstrip between the two thinned pieces, the joint is sloppy in that the backstrip is high in some spots and low in others and the two sides are not perfectly in the same plane.

Because of all that I was worried that the joint would be weak, so I decided to put in a pretty wide inside backstrip to reinforce the joint. With the trim, the width is about 1 ¼”. I think it looks ok. Hopefully I can now smooth the outside of the back, now that I think the whole joint is strong.

It was either all that or give up.

[Kevin Sjostrand]

Looks like you salvaged the back and it should work now

[Stray Feathers]

Your embellished back graft actually looks quite classy - you might start a trend!