Sanding between Coats of Finish

[George Bokros]

The question is, use a sanding block to sand with 320 and 600 grit sandpaper between finish coats or just use your hand to back the paper?

Second question, if using a sanding block use one with a soft face or a hard face?

Thanks

George

[Prashun Patel]

It's always best to use a firm - but not hard - sanding block on flat surfaces. This provides a good balance of keeping a level surface while not being too aggressive.

I adhered some scrap cork to little 2x4 squares, and that level of hardness is about right for me. It's most critical to use a sanding block near edges do prevent rolling over the edge. When I take shortcuts (read, often) and don't use a block, I have this problem despite being mindful.

[Steve Schoene]

Generally I agree with Prashun. I do sometimes make reproductions of early furniture that has hand planed surfaces that aren't fully refined and totally flat. In that case I do use folded paper backed with fingers. That way the surface is not overly flattened. I seldom go beyond 320 grit between coats, with 400 grit the finest I would use on film finishes. Finer grits are used on the last coat as part of a rubbing out process, after the finish has had plenty of time to cure--like a month.

[John TenEyck]

I take a slightly different route. I use Norton's 320 Contour Sanding Sponge, like this: http://www.amazon.com/Norton-02653-C...sanding+sponge, except in 320 grit, which I'm having trouble finding more of at the moment. I back them up with a rubber sanding block. The benefit of using theses sponges is they will adapt to slight surface irregularities and thereby avoid cutting through your finish, which is a problem I've had using regular sand paper. When these sponges get worn they are ideal for removing any little nibs after the final coat of finish; they leave no scratches on anything except the highest gloss, which almost never use. These sponges were a game changer for me. 3M's equivalent cuts much more aggressively, and are unacceptable for me.

John

[Prashun Patel]

This is very good to know. Thx.

[Jay Park]

I use a felt pad with my wet/dry 400G sandpaper. ( I don't go finer than 400G only because I'm to lazy to order 320G)

link

the other important part is lubrication, water or Mineral Spirits. I prefer MS as it does a small bit of filling and leaves a bit smoother surface.

Jay

[John TenEyck]

Why do you use lubricant when sanding between coats?

John

[Bill Neely]

I take a slightly different route. I use Norton's 320 Contour Sanding Sponge, like this: http://www.amazon.com/Norton-02653-C...sanding+sponge, except in 320 grit, which I'm having trouble finding more of at the moment. I back them up with a rubber sanding block. The benefit of using theses sponges is they will adapt to slight surface irregularities and thereby avoid cutting through your finish, which is a problem I've had using regular sand paper. When these sponges get worn they are ideal for removing any little nibs after the final coat of finish; they leave no scratches on anything except the highest gloss, which almost never use. These sponges were a game changer for me. 3M's equivalent cuts much more aggressively, and are unacceptable for me.

John

John, I decided to try the Norton Contour pads - they have the 320 grit at Peachtree, I ordered some yesterday.

Questions: Have you tried the Norton Soft Touch pads? Do you use a softer rubber sanding pad, or does it matter?

Anyhow thanks for bringing this product up, I'm looking forward to trying the pads, I have a bunch of drawer fronts and doors to finish.

Thanks, Bill

[John TenEyck]

John, I decided to try the Norton Contour pads - they have the 320 grit at Peachtree, I ordered some yesterday.

Questions: Have you tried the Norton Soft Touch pads? Do you use a softer rubber sanding pad, or does it matter?

Anyhow thanks for bringing this product up, I'm looking forward to trying the pads, I have a bunch of drawer fronts and doors to finish.

Thanks, Bill

Bill, thanks for pointing out that the Norton Contour Pads are available at Peachtree. I'll have to order some right quick. Sorry, no experience with the Soft Touch Pads. I'm curious how they differ from the Contour pads. Does anyone know?

I use a regular rubber sanding block; the same one I use with sandpaper. It's pretty stiff; not soft at all. The sponge backing on the Norton Contour pad provides plenty of cushion by itself and let's it conform to any minor irregularities in the surface I'm sanding.

John

[glenn bradley]

The usual answer; it depends. If the surface is dead flat or you are building film for a reflective glass-smooth look, I use a hard cork block. When I am doing a glossy flat surface, this is my go-to. For less severe surfaces I have a hard rubber block that I place a scrap of syntho-pad between paper and block to make a cushioned block. This is particularly useful for thin topcoats of shellac where it is easy to sand through. If I'm laying on a thick coat of several mil of modified-phenolic film, a harder block (cork or felt) works better for me. I will also alter my approach with the gloss level I am trying to achieve. A hard block creating a super-flat reflective surface works great for high gloss if the customer wants it (although I am a welcoming satin finish man at heart).

[Kent A Bathurst]

I use 3M GOld 320 or 400, in my hand - pressure on the heel of my hand, paper under my fingers/fingertips - the fingers keep an even contact with the surface, I go for "zero gravity" for pressure. I am going for the lightest touch I can get, and I can't do that via block.

When I get to the last 1 or 2, I will go with Glenn, to move to a flatter surface - especially when I plan on rubbing out.