How long to wait to rub out ArmrSeal between coats?

[George Bokros]

How long should I wait to rub out ArmrSeal between coats? What do you recommend to use --- 0000 buffinjg pad, 320 grit between coats 3M sand paper, 600 grit paper?

Thanks

[John TenEyck]

George, I take it you mean how long do you wait for one coat to dry enough to scuff sand and apply the next, right? Rubbing out is a term generally used to describe the leveling/polishing process after all finish coats have been applied. Anyway, a lot depends upon what wood you are applying it to, at least for the first couple of coats, how thick you apply it, the drying conditions, etc. For me, I generally have to wait at least 12 hours and sometimes as much as 24 hours for the first coat to be hard enough to scuff sand without clogging the sand paper. With subsequent coats, 8 - 12 hours generally is sufficient. Applying coats before the ones underneath are dry enough to scuff sand just retards drying/curing of the subsequent coats, so I try not to do it. From my perspective, you want to apply each coat uniformly so that all you need do between coats is knock off any nibs. For that purpose, I really like Norton 3X Contour Sanding Sponges in 320 grit, backed by a rubber block. They work great to avoid cutting through on edges and corners, yet still cut off nibs efficiently w/o being too aggressive. 3M's product, on the other hand, is far too aggressive, IMO, at least at equal grit. If I have applied dye to the wood, I generally don't scuff sand until after I have applied two coats for fear of cutting through the finish and dye on the edges.

John

[George Bokros]

Thanks John. You are correct I mean buffing between coats. I cannot find any where to buy the Norton 3X sanding sponges, every place I look on line they seem to be unavailable.

[George Bokros]

John is this what you use?



http://www.ptreeusa.com/images/logos/norton_logo_150.jpg
3X Contour Sponge
4-1/2" x 5-1/2"



http://www.ptreeusa.com/images/257_contour_sponge_300.jpg
The Norton 3X Contour abrasive sponge flexes for hand-sanding of contours and small diameter objects. One face of the sponge is coated with aluminum oxide grit, which is one of the most common choices for general purpose grinding of wood, metal, plastic, and fiberglass and is more durable than silicon carbide grit. The tear-resistant foam sponge retains grit up to five times longer than standard sandpaper. The abrasive has been treated with a water-based zinc stearate coating that prevents clogs from forming and can be used in wet sanding applications. The abrasive and bond do not contain dyes, so colors will not transfer to the workpiece. After sanding, the sponge surface rinses free of dust and chips and is ready for reuse. The sponge has a closed coat, which extends the abrasive's life, maximizes material removal, and achieves finer finishes on metals and hard materials than an open coat. The closed coat is 100 percent covered with abrasive grains and is only recommended for use with non-clogging materials.

Features:



3X CONTOUR SANDING SPONGE
Thin, flexible, single-sided sanding sponge for sanding small diameters, curves and contours
For sanding of wood, metal, plastic, paint, ceramics, and drywall
Durable, abrasive coated foam easily conforms to shapes and contours
Washable and reusable

[John TenEyck]

Hi George,

The ones I use are yellow: http://www.google.com/shopping/product/16938401462883051176?lsf=seller:9119074,store:3425 699312404527650&hl=en I used to buy them at Rockler, but they no longer seem to have them. Peachtree had them for a while, too, but now they have the pink ones like in your photo, but I've never tried them. I don't know how they differ, but they must in some way so I don't know how they will work.

John

[Kent A Bathurst]

3M's product, on the other hand, is far too aggressive, IMO, at least at equal grit. If I have applied dye to the wood, I generally don't scuff sand until after I have applied two coats for fear of cutting through the finish and dye on the edges.

John

I typically use the 3M 400g or 600g for this purpose. No experience w/ the Norton product.

For adhesion purposes, I scuff sand btwn brush-on coats of varnish, after 24 hrs. For wipe-on, 3 coats 3 hours apart, sit overnight, and scuff sand.

To knock the nibs down, I wait a couple-three coats - and pick up whatever is there at that time. I never saw the need for this every coat.