I recently used Meguires auto compound on a buffing pad (on a random orbit sander) to polish shellac, which had been sprayed, and cured for 3 weeks. The polish initially looked fantastic and I could see myself in the surface, but a half hour later, the surface turned completely cloudy and white when the solvents evaporated. When I applied mineral spirtits the perfect surface returned. I tried scrubbing off some imagined residue with a rag with mineral spirits, but every time they evaporated, same problem. What is wrong? I had to sand off the surface, and start again. Thanks for the help. I like motorized buffing, and get a better surface than rubbing by hand with rottenstone. I had purposely tinted the Meguires with Japan color to prevent any residue from leaving a white color in a crevice or uinfilled pore here or there. Could that have changed the compound?
Jay
Replies
As I recall, Maguires contains water. If so, the water in the polishing compound probably reacted with the finish creating a haze. I'm assuming you used a polishing compound, not a rubbing compound.
Normally, working a finish to a high gloss involves a number of preliminary steps before you get to machine buffing. Sanding with 600 then 1200 paper is the starting point.
Let me say though that shellac is not a good finish to work in the way you want. The finest shellac finishes are very thin and applied using the French Polishing technique. Lacquer is the best to machine finish to a high gloss.
Thanks. I had sanded to 2500 in this case, prior to polishing. I read the Meguires label and while it does not list the ingredients per se, it does say that it contains petroleum distillates. It would therefore be highly unlikely to contain water, which would not be compatible. In any case, I have used it before on shellac with very good results. Something was different this time.
While I agree that french polishing is a nice technique, it is not the only way. Shellac is probably the most versaitile finish out there. Once shellac is cured, it can be machine polished as well as lacquer.
Jay
If you don't get an answer here, you might post it to Jeff Jewitt at his forum at http://www.homesteadfinishing.com I would love to know what caused the problem, so please let us know when you find out.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
On a similar note:
Meguiars Gold Class paste wax will provide a mirror shine over shellac, but only over glass smooth shellac (prep'd in the usual manner). I use it on occasion for a high shine on 'conserved' pieces that cannot take a french polish due to surface damage but do benefit from the gloss.
It dries white in the cracks of an aging surface, so a little color in the paste is wise.
This forum post is now archived. Commenting has been disabled