Am I the only one who has difficulty with 3/4" MDF? I can't keep a circular saw nor jigsaw on a straight line with this stuff. My spin saw chatters and whines and smokes and breaks bits (Using the circle-guide for cutting subw-holes is a joke). My brother-in-law's cheap-a$$ table-saw doesn't like it either but that's another story. I went to home depot and the tool guy sympathized with me, he was awesome in that he took various router/spinsaw bits out of the display case and tried them on a scrap piece of 3/4 MDF. We tried various types of bits including cement-cutting bits (why not?) but the results were the same as mine: chatter, smoke, stalling equipment.

My question is, does anyone have very positive experience with certain spin-saw bits or jigsaw blades through this stuff? It's funny I never remarked much problem before but I haven't been at it for a while and my latest project its like I'm working with 3/4 steel. Maybe I got a bad sheet (e.g. HDF instead), has this happened to anyone? lemme know what you think out there.

I've never tried a "spin-saw" on the stuff, but my cheap-ass 3 amp Mastercrap jigsaw works great. I don't mean to state the obvious, but just in case...you are using a wood blade, right? I've seen it before.

Warren.

Rotary saws like the Rotozip or any of it's clones were never intended to cut wood as thick or as dense as 3/4" MDF. It's for light-duty stuff like drywall or thinner MDF. No suprise that it's hard on it. I have a basic BD jigsaw and it's not a problem with 3/4", nor is my $99 BD router.

Well a lotta Home Depot employees don't know much about wood working and such unless you get the old dudes, then you're set.

As for using a rotary spin saw, you'll need to use a high quality wood bit. I've found that the "Rotozip" brand works very well. In addition, the saw itself is really important, cause some brands don't have high enough speeds to cut through MDF. I've tried the Mastercraft one and it struggled like crazy to cut MDF. Whereas the Rotozip or Dremel ones went through the MDF easily.

But i only use the spin saw to cut the speaker holes with the circle adapter. The cut is awesome and quick the set up, much better than using a router or a jig saw.

For all other cuts, any table saw will work effectively. With table saws, use good quality carbide tipped finishing blades. You can use sparser blades which will be quicker, but if you have time, use the finishing blades. They give a very nice cut and helps with fitting the box together.

I found that "Freud" brand circular saw blades seem to cut it pretty nicely. I think Home Depot has them, not cheap though....

in my experience using a rotozip, they are great with 1/2" mdf they power right through but 3/4" is another story you have to take a few passes and don't push the bit cuz they will snap like crazy, adjust your speed or the bit will tend to burn, as for table saw's try to get a blade that has around 70 plus teeth this will give you a good clean cut for the jigsaw I like the boush bits there very agressive and bit the mdf good.., but all in all if you are cuttting out holes you have to go with a router , but get one with variable speed or you smoke bits like crazy..,

In my table saw I am using a Razorback brand 'combination blade' with something like 40 carbide tipped teeth. Kinda noisy but eats MDF easily.

For jigsaw blades spend a little more and get Makita, Craftsman, or the best Mastercraft blades that are actually honed and not just stamped. These cut very well.

For a skill saw I like to use a 40-50 carbide tooth blade. Make a cutting board for it to follow and you'll cut as straight as a table saw.

IMO Rotozips are garbage and the money spend would easily buy a router and spiral cut bit.

Get better tools. I have never stalled a single Milwaukee tool EVER. It will rip my arm off before they stop doing whatever they are being told to do.

For circular saw, I like the Diablo blade. Jigsaw, my stock poop ones that came with my Mastercraft jigsaw works really nice.