Official Luthiers Forum!

I am sanding Zircote for the first time. I can run it through my thickness sander only a few times before the sanding belt is ruined from being "gummed" up. Any suggestions on the best way to sand Zircote?

_________________
John Ressler

1) coarse sandpaper. 80 grit max, and consider 60 grit.

2) light cuts. many passes.

3) if at all possible, feed at an angle, so that the grain is not perpendicular to the drum. Then take the next cut angled the other way, so your cut crosses the scratches from the previous cut. There are lines in the grain that have more resin, and if they stay lined up on the same spot on the drum, like when you feed straight in, you get buildup right away.

Drum sanding resinous wood is a big PITA. You either get a wide belt sander with an oscillating belt or get a bunch of patience and extra wraps. In my experience, ziricote is not the worst.

_________________
Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

They sell big blocks of rubber to clean the belts.

John, I feel your pain since I am doing the same thing right now. 60 grit, 30-45% angle, light passes does help but it is still a pain. Also, make sure you have as much air flow as possible. Personally I haven't had much luck with those rubber blocks.

On my sander when part of the belt begins to gum up the machine gives you some feedback. If you stop immediately and pick that part off you are better off, otherwise two more passes and its gummed up good.

_________________
David White, Toronto

"All my favourite singers can't sing."

What everyone else said is excellent advice! The more airflow and higher powered dust collection you have can make a big difference even if it is only keeping the heat down some. If it does start to gum up you can work a razor blade under the big smears and get the edges up and then go at it with a stiff wire brush. Don't do this with the dust collection on as it can make some sparks. Other than that, sand at the fastest speed and take super light passes with the coarsest grit you dare. I haven't been able to get 36 grit to gum up but it leaves some nasty scratches. You can kind of even them out by sending it through 4-5 times for each turn and feeding at different angles, but still leave a healthy amount for the finer grit to be sure.

_________________
Burton
http://www.legeytinstruments.com
Brookline, MA.

Thanks for the help everyone. I guess I'm too impatient - I'm definitely trying to remove too much at one pass judging by your comments. A few ruined expensive wide belts has a way of curing impatience I guess.

_________________
John Ressler

Could not agree more, Cocobolo is nasty.

Fast, light, angled, 60-80 grit, good vaccume. That is the ticket. You will have trouble if the heat rises and cooks the resin hard on the paper.

Rich

I just bought some Ziricote that is 5 mm thick.
Whats your experience planing it. Do you think I could get it a little closer before I ruin to much sandpaper?
Peter

60 or 80 will last you just have to keep the heat down. Follow the advise above and you will do fine. Be sure to take a couple passes before you adjust the sander, and stick to 1/8 turns. This allows you to run the belt full speed(which runs cooler and takes lighter passes). Be sure you ease into the first few passes if it is ruff cut. You don't want to accidentally make a big adjustment.

You want to run like this when your surfacing; Ebonies, rosewoods, padauk, bocote, Zircote, Purpleheart and so forth. Some light colored woods like fair speed to prevent burning even though they don't clog like Maples, Alder, Birch and so forth. Some woods like Mahogany, Spruce, Limba, Walnut and so forth are not picky at all, and sand very easily.

Rich

Every set will be different Peter.

I built with Ziricote earlier this year and it didn't gum up the sander, it bent easily and didn't split or crack.

I'd be trying it on your sander before passing judgement.

Here's a pic

_________________

------------------------------------------------------
Bob Connor
Geelong, Australia

Just to buck the trend here...for milling I actually use a thickness planer and set the pieces on a 10" wide sled that I planed out of construction-grade pine 2x12. The sled is faced on one side with 80-grit paper, that's the side the piece sits on...the whole works slides through without shifting. If I'm afraid of tearout, I'll spritz the piece with water before feeding it into the planer. I've never had a problem thinning down to 0.12" or so in increments of less than 0.01 with any oily wood, and the surface is very nice with sharp knives. If I find that the sled goes out of true (which it can), I just remove the sandpaper and replane it. This has worked very nicely with ziricote, cocobolo and bocote (the 3 worst gummers in my experience).

Since my planer is only 13" wide, of course this does not work with a jointed back....for that I'll go to the 16/32 thickness sander and use the shenanigans that have already been mentioned above.

_________________
The member formerly known as erikbojerik....

Thanks for the advice guys.
Hey Bob, that is one nice looking back!!!
I do like the idea of using a sled with the planner but for what the Ziricote cost I don't think I'll risk the tear out, I'll try 80 grit on the sander.
Thanks,Peter