Grit recommedations on thinning back and sides

[Maniscalco]

I need to thin some really nice Koa I received for back and sides. So far I've been able to get these thinned and almost ready to go with a little sanding. These boards however are about 3/16" or 5mm thick and I need to thin them down to size. I have a drum/thickness sander but was wondering if there's a recommendation out there for paper grit. I have everything from 60 to 220 grit available. I tend to be cautious when sanding and use pretty high grit to prevent issues but I fear that too fine a grit might wear fast and start to scorch the wood.

If anyone has experience with this I could sure use your advice.

Thanks!

[redir]

I use 80 grit on my Jet drum sander then finish off with a scraper. You need to remove a lot of wood so may as well make it quick with a lower grit paper. I find it easier to finish with a scraper rather then struggling to get another grit on my drum

[Maniscalco]

Thanks for the advice Redir. I'll give it a shot. Agreed on replacing the paper on the sander. I have an older Perfomax 16-32 (from before Jet bought them) and changing paper is a bear! Thanks again.

[Fathand]

I use 80 grit then 150 grit

[Bruce Sexauer]

My double drum thickness sander is loaded with 80 and 100. I hand sand the inside of my plates to 180. Koa varies in density quite a bit. If it is the harder stuff I currently like around .80 for the back, and a bit less for the sides. These numbers vary greatly among builders.

[Maniscalco]

Thanks for the advice. It served me well. And hello Bruce from a fellow Petaluman. I think you and I live a few blocks from one another. Small world.

I do have another question about Koa. The sides I bent turned green in the process. I followed the usual steps of dampening the wood and wrapping them in aluminum foil then sandwiching between the steel plates and blanket. The wood bent easily but was a weird greenish color. Do any of your know of a method to avoid this with Koa?

Thanks again for the help!

[Fathand]

Originally Posted by Maniscalco

I do have another question about Koa. The sides I bent turned green in the process. I followed the usual steps of dampening the wood and wrapping them in aluminum foil then sandwiching between the steel plates and blanket. The wood bent easily but was a weird greenish color. Do any of your know of a method to avoid this with Koa?

Thanks again for the help!

I haven't bent koa but I found using distilled water helped reduce mineral staining on some other woods. I know some people wrap in parchment paper before the foil, maybe the aluminum reacts?

https://www.lmii.com/blog/2019/10/02...hooting-guide/