A useful tool from Grizzly Industrial, a company I no longer do business with. This article originally appeared in American Lutherie.
As you will see, this is a favorable review of a product from a company I will no longer do business with for reasons you can read about in the post publication notes following the review. For a long time Grizzly was the only importer to offer these inexpensive rolling pin sanders, but fortunately you can now get these from reputable companies like Industrial Abrasives Co. They call these "cushion contour sanders" (CCS).
Last updated: September 11, 2018
Copyright © 2002 R.M. Mottola
Originally published in American Lutherie #71, Fall 2002]
The item reviewed in the following paragraphs was purchased by the author at full price through normal sales channels. A draft of this review was sent to the manufacturer/seller prior to publication so that any factual errors could be corrected.
My brother, New York sculptor Milo Mottola, has used a hand held pneumatic drum sander (also called an inflatable drum or pump sander) for years, for all sorts of shaping operations. He has recommended one to me many times but I could never get past the fact that his, made by the Sand-Rite Manufacturing Company (312-997-2200, http://www.sand-rite.com ) cost $267 in American money. Call me cheap, but for some reason I could never bring myself to spend that kind of cash for a drum sander with a handle on it, no matter how useful it may be. Grizzly Industrial recently introduced such a sander which sells for $49.95 in the 1.125" diameter size (Grizzly Industrial model H2881). The drum is only 4" long (as opposed to 7" on the Sand - Rite) but for my purposes that was not much of a disadvantage. I bought one, used it for a while, and found my brother's raves about this style of tool to be quite true.
First, a little background on this type of sander. It is a drum sander, but the drum is really a soft inflatable spindle with a solid rod going through its axis. The sanding sleeve that goes over the drum is made of flexible cloth. It's really just a very short sanding belt. You inflate the drum with a bicycle pump. If you pump it up a lot the drum is hard and flat and can be used like you would a rigid drum sander. If the drum is only partially inflated it is very compliant. This lets you sand curved surfaces like neck shafts with ease. As you push the drum down to the work it kind of folds over the surface. The result is a very nice finish on contoured surfaces. Stringed instruments have many such surfaces.
Pump sanders come in a variety of configurations which can be mounted on drill presses, lathes, or other rotating stationary tools. In his review of thickness sanders in American Lutherie #69, Harry Fleishman mentions that one is available as an accessory for the Delta 31-250. There are also dedicated stationary pump sanders available. These generally have two drums. Drum size varies from unit to unit, with 1" diameter being about the smallest and 6" the biggest. As a general rule of thumb, you'll want to use the biggest diameter that will fit into your inside curves. The Grizzly Industrial H2881 is a hand-held model, with a rolling pin-like handle on one end and a shaft you can chuck into a drill or air tool on the other. You get an amazing amount of control with this style of sander as you are holding the thing with both hands.
I have been using this for the sides, rounded over edges, and inside the cutaways of electric guitars, and for neck shaping. Since getting this tool my general approach to necks is to rough them out using the traditional lutherie tool for that purpose (the stationary belt sander) and then to finish them off with the pump sander. The whole process is very fast, and the pump sander makes short work of the curves around the heel and volute. Highly recommended. Dust collection is a potential issue as with any hand held power tool, but in my work I find that I tend to use this sander at pretty low speeds, which keeps the dust from flying.
It took me a while to get the hang of pumping the thing up, something you need to do a couple of times a week, as it does leak air from somewhere. The drum is small so just a few strokes of a little pump are all that are needed. If you pump it up too much you can easily split the sanding sleeve - I've ruined more than one sleeve this way. And if it is pumped up just right, you lose a little air when you disconnect the pump, so it ends up too soft. The trick seems to be to pump it a little firmer than you want it, disconnect the pump, and then bleed out a little air to bring it down to the right degree of firmness. Most places that sell pump sanders sell an inexpensive little low volume low pressure hand pump to inflate these things. Unfortunately Grizzly Industrial does not. Try Woodworker's Supply (http://www.woodworker.com, 800-645-9292), part# 956-287, $10.99.
The Grizzly Industrial H2881 appears to be very well made and very heavy duty. There aren't a lot of parts that would wear out, in fact, there aren't a lot of parts, period. The inflatable rubber drum is probably the thing that would go first, but I couldn't even guess how long one would last. Grizzly Industrial also sells another unit, the 2.25" diameter H2882 for $79.95. Stationary inflatable drum sanders are also available. Sleeves for the sander are available from Grizzly Industrial, too. Since sleeves are really just short belts you can get these from any custom belt maker.
In product reviews I generally like to share my experiences dealing with the company as well as with the product. Grizzly Industrial has such a large presence in the woodworking industry (and even more so to luthiers as they have recently added many lutherie specific tools and supplies to their product line) that most folks have had their own experiences with them, so I'll only say a little bit in that area. On the plus side, I've found them to have competitive prices and to ship very quickly, for items that are in stock. Another plus (and this is a big one for my one-person shop) is that the trucking firm they use to ship big and heavy items to me has drivers that will help me get items off the truck. As for the minuses, back ordered items sometimes seem to end up in some kind of warp in the space-time continuum. I waited three months for Grizzly Industrial to deliver sleeves for this sander before finally giving up and getting them from a custom belt shop (Grizzly Industrial president Shiraz Balolia says sleeves are now in stock). I've also found Grizzly Industrial's post-sale customer support policies to be less than enlightened. They charge a restocking fee on returned items, and although they have an 800 number for placing orders, it's a toll call to their customer support line. I've run into these when I've had problems with things I've ordered from Grizzly Industrial in the past. For me these are not enough to completely prevent me from doing business with the company, but on the other hand this is not the supplier I go to first, as there are others that don't have pay-to-complain and pay-us-to-take-it-back policies. However Grizzly Industrial does have some things which can't be had anywhere else or, like the Grizzly Industrial H2881 sander, cannot be had at a reasonable price anywhere else.
That said, let me finish up by saying that I am very pleased with the Grizzly Industrial H2881 sander. It is a solid, well made tool that is priced right, and it has greatly reduced the amount of time it takes me to do a lot of the shaping and sanding tasks of stringed instrument construction. It has become an important item in my battery of tools.
12/05 – The little sander continues to work well and is invaluable for sanding the headstock to neck shaft transition and the neck shaft to heel transition as well. I am also using a larger diameter pump sander for neck shafts and electric body edges, but this is a stationary (not a hand held tool).
If the post sale customer support issues at Grizzly Industrial mentioned in the review made me reluctant to do business with Grizzly in the past, the torrent of email grousing I took from them as a result of the publication of this review gave me all the impetus I needed to stop doing business with them altogether. The fact is I can get everything Grizzly Industrial sells at the same or better prices from companies with much more customer friendly attitudes. I no longer purchase from Grizzly, nor will I buy any of the products they wholesale under the Shop Fox and Woodstock International brand names.
2/06 – A number of folks tell me they find using this sander with an electric drill somewhat awkward, and attempt to use it powered by an air powered die grinder. The die grinder is way too fast for this job and doesn't have nearly the torque required either. If you want to use an air tool to drive this sander try a straight air drill. Penn Tool Sells a nice inexpensive one. Their part number is 1331.
10/08 – Great news! Reasonably priced rolling pin pump sanders are now available from Industrial Abrasives Co. They call these "cushion contour sanders" (CCS).