Does'nt routing MDF ruin your router bits ? I heard they put sand there to better resist fire etc.

Does'nt routing MDF ruin your router bits ? I heard they put sand there to better resist fire etc.

There isn't any sand in it. It is a bit harder on router bits than hardwood, but probably easier on them than plywood. I think it's the glues that dull tools. Just don't use HSS bits.

There isn't any sand in it. It is a bit harder on router bits than hardwood, but probably easier on them than plywood. I think it's the glues that dull tools. Just don't use HSS bits.

I am in the final stages of building my JGRO based router and I used HSS router bits to machine all the slots and parts to size on my tiny Unimat mill/lathe. They will work but like everything else in life there are drawbacks. Provided that the cuts are small (in terms of material removed), the feed rate is reasonable and the cutter speed is lower than you might normally use (my Unimat can only manage about 3000 RPM flat out) MDF can be cut with HSS bits (it machines nicely too with clean edges and good sizes). I was able to hold +/- .002" on most dimensions with some of the craziest set ups you have ever seen!

I will concur with the glue though. I had to use a hand held router for one part and the higher spindle speed meant that it was doing more 'burning' than cutting and there was a thick 'gooey' build up on the cutter when I had finished that was probably glue released from the heat of cutting.

Larry

Are there any boards made from wood dust and glue that have sand in them ?

Not that I'm aware of. You wouldn't be able to cut it.

From what I understand it's the resins in MDF that give the cutters a hard time. Use carbide bits...HSS will "melt".

Don't take deep cuts and watch for burning. The resin is what wastes your bits. Use a straight fluted. Porter Cable makes one for MDF. I found them at Home Depot. Paid too much, but it works. I'm cutting our 3/4 MDF speaker cabinets. Make sure you have a VAC attachment. The dust sucks and gets into everything.