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I have a question regarding sanding varnish and laquer. When I have tried this in the past all I seem to end up with is clogged up abrasive paper. I have been using a random orbital sander with 100-grit paper, and was wondering weather to change the type of sander, the grit or both. Any help much appreciated. http://ubb.ubeaut.com.au/ubb/smile.gif
Regards
Andrew.W
WHAT? 100g?
Hang on, are you talking about sanding to remove the old finish back to raw timber or just sanding inbetween coats?
If its the latter, then the lacquer/varnish hasn't cured properly & or your using cheap abrasive paper. In any case you shouldn't be using any grits below 240g for cutting back.
let us know more details.
Cheers!
Sorry for the lack of details. I mean sanding it back to raw timber.
Regards
Andrew.W
Andrew,
I had a disastrous experience in lacquering a redgum table and found that the paper clogged exactly the way you described in the between coats and also when I tried to remove everything. In my case, Shane's suggestion of the lacquer not being dry was spot on. It took weeks before the lacquer was fully dry and the sanding no longer clogged the disks.
This long drying time was, I am sure, caused by the bloody awful job I did in applying the lacquer which after about 10 coats wound up being 3mm thick (hangs head in shame!)
Even a week after the the table was finished if you put a beer bottle on it the bottle would slowly sink into the surface leaving a neat impression which would just as slowly disappear once the bottle was removed.
I'm only now facing up to the task of removing all that NC and re-finshing the table!
Marcus
Marcus - Don't want to sound like I'm picking on you mate. But, this is why you use a professional when you want a good job done. Or at least go and find out the right way to do the job in the first place, like how to spray, what pressures to use, the correct viscosity of the material, the correct thinners, time between coats, etc, etc.
Andrew - what you are probably trying to remove is bloody polyurethane. For starters as Shane suggests get yourself some good abrasive. My preference is for Hermes. It might also help if you were to use wet and dry with water to which a little dish detergent has been added as a wetting agent. This should help to minimize the clogging effect.
I know Shane isn't a big fan of stripper, but for mine, I would be getting the old stuff off with Haymes paint stripper. Save a fortune in paper, whilst preserving some of the surface patina of the of the piece. Especially if it is a fine antique. It is much easier to sand the surface after the finish is removed with stripper but even then you can still get some pretty intense clogging happening from what is left in the pores of the wood.
If the work is covered in poly then sanding is just about your only smart option. An easy way to see if it is poly is to put a bit of stripper on the surface and if nothing much has happened within 5 minutes it is most likely that it is.
Hope this helps.
Cheers - Neil http://ubb.ubeaut.com.au/ubb/smile.gif