Custom Sanding Block How-to?

[91FE]

Hey Guys,

How would you go about making a custom sanding block? I need to sand an edge (solid surface countertop) that has a somewhat complex profile. I've used the rectangular foam sanding blocks in the past on other projects, but I'm afraid they'd be too rigid for this one. I'd like to come up with something simple that I can change the paper on. Any thoughts? Here's a picture of the bit:



... this bit is crazy by the way. B=1-9/16", D=3" and it probably tips the scale at 2+ Lbs.

[rjwaldren]

With a collection of coves, roundovers and careful setups you could route the opposing profile and attach PSA paper. It would be alot of work but would give the best results.

I'm sure you've already had that thought, hopefully somebody has a forehead slapper (Why didn't I think of that) method.

[91FE]

ahhh google...the second love of my life

This will work (from: http://www.rd.com/familyhandyman/content/17573/):

Make a custom sanding block to speed up sanding of complex shapes
Scraps of rigid foam insulation (extruded polystyrene) make great sanding blocks and have the advantage of being easy to shape. The photos show how to make a sanding block that conforms to your molding profile. Make three blocks while you’re at it. Then glue three progressively finer grit papers to the blocks to complete your sanding sequence. If you don’t have any extruded polystyrene, ask for scraps at a local building site or look for a damaged sheet at a home center or lumberyard.
This profile sander has one drawback. It’s difficult to fit the sandpaper tightly into the sharp corners of the custom-shaped block. This can result in rounded-over edges on some molding profiles. To prevent this, slice the sandpaper with a utility knife in the “creases” and press it tight to the block with a putty knife. The other solution is to cut the custom-shaped block into sections to eliminate the parts that could round over a sharp profile. Sand these areas separately with a small square sanding block or a small piece of folded paper.

Click Image to enlarge.
1. Spray the molding and the backside of 120-grit sandpaper with spray adhesive. Stick it to the molding, making sure to press it into recesses with the blade of a putty knife.

Click Image to enlarge.

2. Rub a block of rigid foam insulation over the sandpaper until it conforms to the molding’s profile.

3. Coat the foam block and the back of the sandpaper with spray adhesive. Carefully stick the sandpaper to the block and sand the molding.

[cabinetman]

You might try some "wools", like steel wool. I don't use steel wool as particles will rust. There are many "wools" like bronze, and mineral "wools", which include fiberglass fiber. There are also synthetic "wools" that work well in sanding those types of profiles. Most of the "wools" are available in different grades of abrasiveness.
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[poolhound]

Thanks for the tip. I havent needed something this complex but I will store it away for the future.

For most "non-flat" sanding applications I find the synthetic "wool" pads work well for me.

[91FE]

Ahhh... here's that forehead slap. Never considered wool. I'll give that a try first. Thanks.

[poolhound]

Ahhh... here's that forehead slap. Never considered wool. I'll give that a try first. Thanks.

Its worth a try but with complex profiles like yours it will be a challenge to ensure even pressure so you sand all parts of the profile without knocking off edges you would rather keep sharp.