Tuesday, November 9, 2010

Speaking of field jackets....

The gold standard in field jacket opening tools has long been the Stryker Cast Cutting saw, a medical tool designed to open plaster or fiberglass casts on broken bones, and has also been know to crack a calvarium or two. The advantage of this tool is that the blade oscillates through a very narrow range of motion, thereby limiting the amount of cutting possible per contact with a given surface (i.e. won't damage soft tissues easily). Since it doesn't make a full rotation, it is easier to control, safer, and throws slightly less dust than a circular saw.  While generally long lived, the downside of these great tools is that they can cost several grand when bought new. Used they sell for about $500, but it is very hard to judge the condition of a potentially abused saw like this. I've seen several "As Seen On TV" infomercials advertising similar products (like the Fein Multimaster, which I've always wanted one of), and those generally run around $200 as well.

On a trip to Home Depot last week, I came across two $99 varieties of the Stryker-type oscillating tool. This blog has done an apparently thorough job of reviewing the full gamut of available tools, I haven't read most of them, and am just reporting on my experience so far with one of them. Home Depot had both the Rigid JobMax and the Dremel MultiMax available. After walking around with the Rigid for awhile, I put it down and bought the Dremel, for two primary reasons. The Dremel is corded while the Rigid tool is battery powered, one hassle that I'd rather not deal with is batteries running down mid-job. The second reason was very practical, the Dremel display had a whole rack full of replacement blades (for ~$10) while the Rigid did not. So far, I've been very happy with the Dremel Multimax, I'm about halfway through opening a large field jacket, and the tool has been a trooper. The function is very similar to that of the Stryker, feels much lighter and easier to handle over a long use, and doesn't seem to overheat nearly as rapidly as the Stryker does. The M-PACT cast cutting saw that was in the lab when I arrived (and which looked virtually unused) burned up the first time I used it on a large jacket. We'll see how the Dremel holds up over time and I'll report back then, but for now I'm pleased.


BJ and/or Lori Nicholls said...

I have a Dremel Multi-Max at home for remodeling work. The blade selection for the tool is quite limited and blades are relatively expensive. For cast cutting, I'd guess you'd primarily use the crescent-shaped drywall/wood blade. That blade doesn't cut drywall very quickly, so I doubt it's capability cutting harder plaster and burlap layers.

Here's a source for less expensive aftermarket blades (mostly carbide-grit blades):


I picked up some bimetal blades from another source —Imperial Blades, but their website isn't operational so I don't know if they're still in business. The blades are much more robust than any of the Multi-Max blades. Suitable for cutting nails, albeit slowly with the Dremel tool.

Frankly, I think the really cheap Harbor Freight oscillating tool (usually under $40) would be a better choice for opening field jackets. The blades are cheap, the tool's body is cast metal, and I'd bet the tool lasts longer with constant exposure to plaster dust than the more lightly built Dremel.

Another tool that's in the ballpark of the Multi-Max price is the Rockwell Sonicrafter, now sold at Lowe's. It gets good reviews on Amazon.

iPreparator said...

The curved wood/drywall blade actually does wonders getting through the plaster and burlap, it is essentially the same thing that Homer Stryker patented in 1947 for use in opening plaster casts. Toothed curved blades will be the safest route to attack 95% of field jackets. Piranha has one of these for sale for $10, but their shipping cost is $12 per order, while Home Depot stocks the Dremel blades for $10. Remember, the goal is to cut through the field jacket slowly, every time. Always.

Now, I've got a well publicized personal policy against shopping at Harbor Freight. I feel like I'm cutting enough corners by eschewing the undoubtedly well constructed and long lived German tool and halving the price to the Dremel (I'll probably buy a Fein soon anyway), I've got no desire to have yet another pewter bodied Chinese P.O.S. Harbor Freight tool irreparably break after an hours use. However,YMMV.

Anthony Maltese said...

Meh, I still prefer a Harbor freight 4 1/2" angle grinder with a diamond wheel. Nigh disposable equipment, and the blade works a good long time. Also handy for getting through ironstone concretion!