Tips for Blackwood

[DougBrown]

I started working with African Blackwood for the first time making boxes. I find that a touch of the sapwood is a nice feature on a box especially against the Blackwood. My problem is when sanding and finishing(I'm using lacqer) I end up staining the sapwood. Anyone have any tips for keeping that creamy color? Thanks, Doug

 

[john lucas]

I've never turned blackwood but have done segmented work with woods that carry over the sanding dust and stain each other. I put a layer of sanding sealer over the wood before I sand and sometimes even between each grit.

 

[dkulze]

You can blow out some of the dust with high pressure air. Also, give eurythane a try for stabilizing before the laquer.

Dietrich

 

[Jake Debski]

You can blow out some of the dust with high pressure air. Also, give eurythane a try for stabilizing before the laquer.

Dietrich

Dietrich, won't the laquer lift or soften the urethane?

 

[Bill Turpin]

Sealing keeps out the dust

The fine dust that colors the sap wood will not be absorbed. After all the sanding is done the black will not bleed over, even if all the finish is removed.

Bill in WNC mountains

 

[Bill Boehme]

Dietrich, won't the laquer lift or soften the urethane?

No, it is the other way around if you applied lacquer first.

Bill

 

[woodwish]

I've never turned blackwood but have done segmented work with woods that carry over the sanding dust and stain each other. I put a layer of sanding sealer over the wood before I sand and sometimes even between each grit.

John- good advice! I tried this with a walnut and maple platter I was working on tonihgt and it does work, wish I had heard about earlier. Thanks again.

 

[John Nicholas]

Sanding Bleed

You might try a Naptha wipe off to get the lighter colored wood cleaned up.

John

 

[john lucas]

I was making a Padauk and maple piece one time and had tremendous problems keeping the orange padauk dust out of the maple. Mark Baker of England was having the same problems and we were both talking to everyone we knew. Someone in Mark's country suggested the sanding sealer technique. Since I had tried just about everything else I gave that a try.
The problem with sanding different colored woods like this is the sanding dust from the darker wood filling the pores of the lighter and vise/versa. You can achieve some success by blowing out the dust inbetween each grit but dust can be pretty tenacious. Filling the pores somewhat with sanding sealer helps keep the dust out and also helps it let go when you blow it off with the compressor.
This method also works well when sanding bowls that have light sap wood next to dark wood like Walnut. It also helps when sanding light colored natural edge bowls that have a dark bark. I've had the dark cambium layers smear into to the light wood.
You don't always have to coat the wood between every grit. Once you get to the finer grits you may be able to skip a coat but I only do this 220 and beyond and even then I'm cautious. Usually too much work has gone into a segmented piece at this stage to mess it up sanding.

 

[Jake Debski]

No, it is the other way around if you applied lacquer first.

Bill

Bill,

Just so we are talking apples and not apples and oranges, urethane as in poly urethane eg. minwax, varathane, etc?

 

[Angelo]

Blackwood

Doug,

If you are talking about the box you recently posted. I don't see a problem. If you are talking about the black specs in the sap wood, I suspect that sanding dust is getting into the pores of the wood. There I would use a coat or two of sanding sealer before sanding the black part. SHould keep the dust out of the voids.

A

 

[DougBrown]

Blackwood Dust

Thanks everyone. Yes I was referring generally about the piece I posted titledThanks Ray. It looks ok in the photo, but it did noticeably darken the sapwood.
The sanding sealer sounds like the way to go. I give it a try, Thanks!

 

[JerryG]

Blackwood Dust

I work often with Holly and dark woods (Holly is the worst wood for picking up dark dust). I found this to be very helpfull. After initial sanding with 3X paper 120 grit, put a penetrating oil on the light wood only. If you put it on the dark wood it will clog the paper and stain the light wood. Move on to 220 grit and repeat the oiling process. Two things to remember:
Let the oil dry (add some thinner to speed drying) before sanding with a higher grit. And, clean the dark dust off the paper and your hands before each sanding.

Good Luck!