Ocillating tool [Merged threads]

I do acres of drywall repairs, usually behind plumbers who make quick, oddly shaped holes and throw away the pieces. To close these holes I first cut them square. I have been thinking about investing in an oscillating tool to make these cuts but I have some questions.
First How much dust does an oscillating took make in cutting drywall? I don't want to have dust in the whole room. Compared to cutting with a drywall jab saw how dusty will it be?
Second Are the cuts enough faster than doing it by hand to make it worth dragging another tool into the house and putting it away afterwards and hauling it around?
Third How long will a blade last in cutting drywall and how expensive are the blades?

I suppose were I to buy an oscillating tool I would find other uses for it but my primary use as I see it now is to speed up cutting or reshaping a hole in drywall, maybe occasionally plaster. Is it worth it? Remember I want no more dust than doing it by hand.

 

I've seen the generic knock off that Harbor Freight sells, on sale for less than $15 so you might want to experiment with a cheap one before investing in a more expensive one. Some brands also have cordless models.

I've not used my HF multi function tool on drywall but have been pleasantly surprised on how handy it is on the jobs I have used on. I don't think it would cause any added dust and the blade should last a long time on drywall .... plaster might be different.

 

1). It makes more dust than cutting with a utility knife, but significantly less dust than using a drywall jab saw, sawzall or jigsaw. Mainly because the blade is thinner and finer. Most of the problem with dust is created when the motor of the tool blows the dust around. The motor is small and the motor vent fins are a long ways from the blade so most dust that's made falls straight down. Cutting with the tool in one hand is easy if you want to hold a shop vac hose with the other. That's the best way to eliminate 99% of dust in the first place. The place the oscilating tools are nice is for making a nice clean corner cut. So I could see you use it in combination with your existing technique... but use the oscilating tool to make the nice corner cuts.

2). I would say no it's definitely not faster. If you use the circular half-round blades they are pretty slow, comped to just scoring with a sharp knife a few times. It is less work, though. The tool makes most jobs easier... and more precise, but not necessarily faster. I've recently started using some knock off blades for my Fein that are 2 2/3" wide and have the Japanese shark teeth. They are really fast compared to the fine tooth blade I mentioned earlier.

3) The knockoff blades I found on Amazon are reasonably priced at about $5 or $6 a blade when you buy them 10 at a time. They last a long time in drywall as long as you don't hit a nail with them. I've also purchased the half circle blades from ebay for about $10 ea when you buy 2 packs of 2. I think they last forever in drywall, provided you don't hit nails or dull them by cutting a lot of hard wood.

I wouldn't recommend it for plaster... you'd probably want a narrow diamond blade for that which I haven't tried. And it would be very slow and make a lot of dust since it would basically be hammering the plaster into a powder. I would think a diamond sawzall blade would be best for plaster, although very dusty.... its probably not as dusty as a grinder and diamond wheel.

 

To be honest, I even gave up on the hand drywall saw. I score a straight line with a utility knife and then make 4 or 5 passes with the same blade to remove. Less dust than any of the previous mentioned methods. I have a multi-function unit that begins with the letter "D" and ends with an "L". Blades are $19 to $25 (which burns me every time I buy one). The thing about drywall is that it clogs the blade teeth which keeps it from cutting and staying as sharp as it is out of the box. Truth is the majority of use of the multi tool if for under cuts on door jambs and the grout saw attachment for doing tile repairs.

Yes, you will have more dust than your hand method.

 

Far faster, no burr in the paper like when you use a hand saw, far more accurate cut, almost no dust.
Every electrician I've let borrow mine bought one soon after.
I own 2, of the Rockwell Multi Crafters and use them all the time doing things no other saw could do.
Removing grout, cutting hardwood floors to do a patch, Sanding window stools and stair treads in the tight spots ECT.