Belt sander clogging

[Ernie Jurick]

I'm refinishing a large handmade Eastern red cedar chest that was built in the 1920s. The exterior finish, which I *think* was shellac, has darkened almost to black and become stained and eroded over the years. I used two applications of a standard paint and varnish remover to get down to the wood surface, then went over it with denatured alcohol until there was no trace of color left.

I then attempted to clean up the surface with a #80 open-grit belt on my sander. The first belt lasted 30 seconds before becoming so badly gummed up that I had to stop. It was literally plated with what looked like brown wax. The wood surface was barely touched. I cleaned the belt with a resin stick and tried again. Same thing. Ditto the third try.

I then switched to a small finishing sander and #60 open grit, thinking that the weight of the belt sander (ancient 4" Rockwell monster) was heating up the wood and drawing residual shellac to the surface. The small sander ran for about a minute before clogging like the belt had. I cleaned the wood surface again with alcohol, then with acetone, and tried a new sheet of paper. Same thing happened.

I'm frankly stumped. A very knowledgable acquaintance suggested running a propane torch or heat gun lightly over the surface to heat up, draw off and carbonize the remaining shellac, which could then be scraped off before I tried sanding again. However, he admitted that he had no experience working with cedar this way.

I thought I would ask this incredible group before going the torch route. It's a family heirloom and I'm likely to be lynched if I screw it up. Any suggestions appreciated.

-- Ernie

[Dave Mundt]

Ok...that sounds like you managed to get the applied finish off.

That sounds more like sap or something like that, rather than residual finish. When you say "clean up the surface", why should you have to start with such a coarse belt? I would think that it would have been smooth enough from the original builder to require nothing more than a little sanding with a 220 grit or so disk.

No...this is what is known as a "Bad Idea". It is my general rule to NEVER recommend a process that I have not had some contact with, although I might say something like "well, I heard that one can..." What will likely happen is that you will end up with a random pattern of scortch marks on the wood that STILL will have to be removed. It is possible to use heat to remove a finish, but, it can be a tricky thing.

Yea...that can be a problem with things of sentimental value. I would suggest this course of action. Put down the belt sander. If it is necessary to smooth surfaces back down, I would STRONGLY suggest using a scraper. It will do a great job, even on this challenging wood. I would ALSO recommend that you pick up a chunk of similar wood from your local lumber yard and experiment on it for a bit, figuring out how to sharpen the scraper to an appropriate angle, finding the correct amount of hook, etc. The big thing is not to mess with it too much. Got to remember that Cedar is not a very hard wood, so, it is a waste of time and energy to try and get all the dents out. You will just lose valuable thickness, and, end up with a smooth surface that will quickly accumulate a NEW set of dents and dings. Unless there is serious damage that needs to be repaired, my usual course of action on a piece like this would be to simply strip off the old, crappy finish, and redo it without really doing much to the wood itself. Sorry for rambling a bit...it has been a bad day... Regards Dave Mundt

[Michael Daly]

Careful, cedar will char very easily. DAMHIKT.

Mike

[Ernie Jurick]

The back of the chest isn't finished, and that cleaned up nicely, which is why I suspect the old finish.

The wood is VERY badly stained. It looks like generations of beer glasses had been set down on it.

I'm glad I asked. :-) I did a lot of online research on eastern cedar last night, and you're right on the mark. Heat would have ruined the surface and I'd be living in the doghouse for months.

I appreciate the pointers, Dave. I have a set of Swedish scrapers and a burnisher I used to use back when I was making furniture. It never dawned on me to use them for refinishing.

-- Ernie

[Ernie Jurick]

Thanks, Mike. I researched cedar last night since I've never worked with the stuff before, and the torch route is definitely NOT the way to go.

-- Ernie

[Dave Mundt]

I see....

Ah...instead of removing stock, then, how about using a bleach to get rid of the stains, then, if necessary a light stain to get the appropriate color back into the wood?

Months? It COULD be one of those things that you hear about for YEARS (I have a couple of those in my past too..*smile*)

It has been my experience (and the experience of others) that a good scraper can be a spectacular tool for taking off old finishes, too...I probably should have thought to mention that earlier. It will often strip off the old finish right at the wood, without messing up the surface underneath. Good luck. Dave Mundt

[Ernie Jurick]

The scrapers worked like a charm, Dave. I even remembered how to use the burnisher after a few practice tries. :-) They've been packed away for 20+ years. In the same box was a Record bullnose plane and spokeshave I thought I had lost years ago. Thanks for the help.

-- Ernie