Sanding after wipe-on Poly

[Brian Kent]

I have gotten this answer before but I can't find my own post.

I am finishing a walnut project. So far:

Danish Oil - Waited

Shellac - sanded to 220

4 coats wipe-on poly

Question: Do I sand now with 150 or is this the step that I go to 400 and above?

After this I'll finish with a couple of coats of wipe-on, let it sit for a couple of weeks and polish.

[Jim Becker]

I'm not sure I'd sand after wiping on the varnish unless more than 8 or so hours passed since the previous coat...the coats are very, very thin. And if this is just before your final coats, you only want to swipe it very carefully to remove any dust nibs. 320 or 400...never 150. Varnish goes on in layers. It's so easy to sand through them, especially when they are wiped on. You don't want to do that as the lines can be quite visible where you cut through, sometimes even after you re-coat if the cut through was bad. Take care on this...

[Steve Schoene]

150 is for bare wood. At some point you need to have let the wiping varnish cure for at least overnight or you run the risk of trapping solvent beneath curing varnish. After doing that you should sand with about 320, lightly. Then I would put on one more "set" of three coats, spaced fairly close together, waiting just until you can touch the surface with a finger and not bring any away. Those three coats, in total thickness about the same as one brushed on coats, should if they are applied that close together, should be able to be rubbed out without witness lines as long as you don't cut through all three. But after putting on that last set you should wait as long as you can--a week at minimum, but a month is better, especially if you are going for a gloss finish.

[Brian Kent]

Thanks, Jim.

It has been about 18 hours and I'll use 400 per your advice.

There are a couple places where I found a sag and drip from the first few coats of wipe on. I appreciate your time.


Brian

[Brian Kent]

Jumping ahead a month, use fine rubbing compound and wax?

[David Romano]

I'd only use 400 if you have alot of dust nibs. Otherwise, stick with steel wool, 0000 grade. Then wax and polish, I don't think you need more wipe on poly.

David

[Brian Kent]

Too late David. I had to sand off a couple of thin drip marks. I have put on my first final coat of wipe-on poly and will finish that off today (hot day - 94 degrees - dries fast) and stick it on a shelf for a nice long dry time.

I have some 0000 steel wool. I'll have to find a way to add another 0.

[Brian Kent]

The Poly layers are finished and the project is on the shelf. I posted the pictures on the General Woodworking and Power Tools forum under "First Two Bandsaw Boxes".

Thank you all for your help.

[Howard Acheson]

>> There are a couple places where I found a sag and drip from the first few coats of wipe on.

I'm a little confused. Why did you get drips and sags? The reason for using the wipe on technique is that it is impossible to get sags and drips. The idea of wiping on a finish is that your are applying very thin coats. It sounds like your wiper had way too much material in it. It should be no more than damp. If you get a shiny surface as you are applying it, you are applying it too thickly.

Although it's my taste, I do not like walnut to have a glossy, plastic looking type of finish. Given that you have applied thick coats, I would not add any more finish. I like a more in-the-wood finish. To get this, I just use a 2-3 wiped on coats.