Replies

1. 
   Steve50 | Jul 14, 2005 04:32am | #1

   Wendy - I wouldn't hesitate to use MDF for a jig but it is an aggressive material.  I questioned my sharpening guy about MDF and blades.  He indicated that carbide will dull more quickly with MDF than with a hardwood.  He also indicated that the factories that cut MDF do so with diamond blades something way beyond what I was willing to spend.

   Steve

2. 
   Dave45 | Jul 14, 2005 05:26am | #2

   Cutting MDF will dull a carbide blade a little faster than hardwoods, but it won't be noticeable until you've run a lot of it thru the saw.  I have several carbide tooth blades ranging from 28 teeth to 60 teeth and they're on a "schedule" that gets each one to the sharpening shop about once a year.

3. 
   nikkiwood | Jul 14, 2005 05:52am | #3

   Carbide tipped blades were originally designed to cut manufactured materials such as plywood, mdf, and the like. More teeth = smoother cuts.

   Don't even think about using a diamond blade in your table saw. These are made for cutting stuff like tile and masonry products.

   Maybe they use some kind of diamond tipped blades in industrial settings, but those things are not available to the likes of you and I.

   ********************************************************
   "I tend to live in the past because most of my life is there."
   -- Herb Caen (1916-1997)

4. 
   RickMath | Jul 14, 2005 07:33am | #4

   Wendy

   I have cut a fair amount of MDF. I wouldn't use a rip blade as it's too agressive. I use an Amana Melamine blade. I has a negative hook (teeth slant away from the cut) that make very smooth cuts. It's a little pricey and there may be other brands that also have this type of blade.

   Make sure you have very good dust collection as mdf dust is really nasty. If you don't have strong dust collection, you'll have a cloud of MDF in your workshop. Amana also makes a similar blade that will fit in a hand circular saw. I have used both and they seem to not dull too quickly. Just clean them periodically to remove the resin used to bind the sawdust together to make MDF. I use CMT's blade cleaner and it works great.

   I don't think I would consider diamond blades for this.

   Hope this helps.

   Rick

5. 
   MatthewSchenker | Jul 14, 2005 02:03pm | #5

   Wendy,
   I agree with everyone here about the way that MDF affects the blade.

   But I want to REALLY agree with Rick about dust collection. This is very important. MDF produces horrible dust. When I was new at woodworking, I didn't think too much about dust collection, and one day I cut a bunch of MDF. That night, my chest actually hurt from the stuff and I was coughing a lot. I decided I would never do that again, and while I was at it I decided to make sure and get better dust collection for plywood, and then for hardwood!

   Here are some links I have collected on woodworking dust. All of these links are to non-commercial organizations concerned with health and safety. These should be enough to convince you!
   http://www.worksafereps.org.nz/hazards/1054849600_10004.html
   http://www.ccohs.ca/newsletters/hsreport/issues/2004/10/ezine.html#hazardalert
   http://www.workershealth.com.au/pdfs/023wood.pdf
   http://www.seqair.com/skunkworks/Tools/Respirators/Respirators.html
   http://www.hazards.org/haz75/tucasthmasurvey.pdf
   http://www.cpcb.nic.in/sept2001air2.htm
   http://www.hc-sc.gc.ca/english/iyh/products/arts.html

   I solved my problem by getting a Festool saw, which collects 95%+ of the dust.

   
   

   ---

   Edited 7/14/2005 7:06 am ET by Matthew Schenker

1. 
   Adrian | Jul 14, 2005 02:20pm | #6

   MDF will dull blades eventually, but you will be able to cut a lot before you need to sharpen. Diamond blades are used in woodworking, but they are petty expensive, and they need a very controlled situation as they are vulnerable to shocks.....so cutting on a manual saw is pretty much a no-no.....computerised beam saw is more the answer.

   For raw MDF and a 10" saw, I'd recommend an 80 tooth ATB blade....this will give  beautiful smooth cut. 80 tooth triple chip grind would be second choice.If coated with melamine, then an 80t melamine ATB with negative hook, or second choice again a triple chip grind.

   Rip and combo blades don't have enough teeth for a smooth cut; chips are too big. cabinetmaker/college woodworking instructor. Cape Breton, N.S

6. 
   ring | Jul 14, 2005 07:07pm | #7

   Wendy,

   I use an Amana 80 tooth blade for all sheet goods, including MDF.  Results are excellent, and there are a lot of other great blades out there at reasonable prices.  I send the blade for sharpening on a regular basis, after about 20 hours of cutting.  The cost of resharpening is really negligible if you factor it into the job.

   DR

1. 
   wendy1 | Jul 14, 2005 11:40pm | #8

   Hi,

   Thanks for the info. I'll see if I have a dedicated cross cut blade downstairs in my workshop. I have a combination blade but not sure If I have a dedicated cross cut blade. If I do it definitely has less than 80 teeth. One of these days I should invest in a quality 80tooth blade.  60 teeth will have to do.

   I won't be cutting too many boards of MDF so for now I'll just use the carbide blade if I decide to build the jig using MDF. (much cheaper than using hardwood or plywood.) Might just go in search of a piece of plywood to make this small tapering jig instead.

   I take it I'm ok using a 40 tooth thin kerf rip blade for cutting plywood. I don't own a dedicated Plywood blade.

   Wendy

1. 
   PlaneWood | Jul 15, 2005 03:48am | #9

   MDF puts out a lot of bad dust when sawing.  Use a big fan to blow it away from you, or better yet, a large DC.  Don't breathe that crap!

   PlaneWood by Mike_in_Katy (maker of fine sawdust!)PlaneWood

7. 
   mike4244 | Jul 15, 2005 09:20pm | #10

   Wendy, are you sure your blade is a rip blade? Most rip blades for a 10" saw are 30 teeth and less. Look at the teeth, if the tip is ground straight across, it's a rip blade. If the teeth are ground at an angle , this is looking straight down at the tips, then its a crosscut. In any event the blade will be fine if it's the only one you own.

   If I have a lot to cut, I put a Freud 80 tooth blade in , made for crosscutting plywood. Otherwise I use the blade that is already on the arbor. I have made occasional cuts even with a rip blade, works fine. As another post mentioned, this material is dusty. Wear proper dust mask and try to collect as much as the dust as possible with your available equipment.Don't be concerned with the blade getting dull, yes it will dull more than wood,but it's not like cutting concrete either.I doubt you would notice any dulling of the blade for occasional cutting of mdf.

   mike

1. 
   wendy1 | Jul 16, 2005 02:51am | #11

   Hi Mike,

   Yup, My saw blade is a rip blade and it has 40 teeth.

   Wendy

    

8. 
   WillGeorge | Jul 16, 2005 08:28pm | #12

   Old post but here goes..

   Unless you cut ALOT of it the only broblem with cutting MDF on a TS is ..

   1.. Pickin' that stuff up
   2.. Breathing after cutting it

   Actually it is GREAT if you do not mind the mess!

   I think my routers make MORE dust than the TS..