MDF: What saw blade and screws to use?

[feke67]

I am about to start a cabinet project and I have a 8.25" table saw. Is there any particular saw blade (blade tip) that I should use to get cleanest cuts on the MDF?

Also, what are the recommended screws to use to help fasten pieces of MDF together? Parts Express and others sell cabinet screws with courser pitch than regulart # 8's wood screws. (I assume glue & screw is best approach).

Thanks in advance!!

PW

[Keithj]

Originally posted by feke67
I am about to start a cabinet project and I have a 8.25" table saw. Is there any particular saw blade (blade tip) that I should use to get cleanest cuts on the MDF?

About a 40 to 60 tooth carbide tipped blade should be good.

Also, what are the recommended screws to use to help fasten pieces of MDF together? Parts Express and others sell cabinet screws with courser pitch than regulart # 8's wood screws. (I assume glue & screw is best approach).

Cabinet screws should be good. Look for course pitch screws with parallel sides. Best IMHO are square drive screws as their action is more positive than philips or pozidrive. Be careful if you screw them into the end of MDF as they can, if pilot holes aren't drilled, either have no strength or split the MDF. There are also glues specifically formulated to use with MDF which, on its ends is fairly absorbent. See if you can get those. I live in New Zealand, so can't give you brands.....
Good luck with your project.
Cheers, Keith

[Dave Bullet]

Hello Keith,

I'm also from NZ - what particular wood glues do you recommend here? I was told aliphatic (excuse spelling) (yellow colour) is better than standard white PVA for gluing MDF.

Also for screws - I was going to use Fortress zinc plated 8g*45mm - ok? (it is 25mm MDF - I know the 1/3rd 2/3rds rule - but thought if screws were 100mm apart and sides glued - that should be enough. BTW - its for a subwoofer- approx 54cm^3 in size)

Any opinions?

Thanks,
David.

[Keithj]

[QUOTE]Originally posted by Dave Bullet
[B]Hello Keith,

I'm also from NZ - what particular wood glues do you recommend here? I was told aliphatic (excuse spelling) (yellow colour) is better than standard white PVA for gluing MDF.

That's the stuff... I'd forgotten the type.

Also for screws - I was going to use Fortress zinc plated 8g*45mm - ok? (it is 25mm MDF - I know the 1/3rd 2/3rds rule - but thought if screws were 100mm apart and sides glued - that should be enough. BTW - its for a subwoofer- approx 54cm^3 in size)

Personally I go for a 50-50 split. The other way is to sink the heads into the MDF. Don't forget to drill 2.5mm pilot holes into the ends of the MDF. No splits that way. And don't stint on the glue.

Cheers, Keith

[Dave Bullet]

Thanks for the reply.

I'm doing a sub enclosure. I'm going overkill (w/ 25mm MDF) - also including another enclosure for the plate amp.... and making it dual sealed / vented by using a threaded PVC port and cap (standard plumbing stuff).

Should be interesting.... I'm going to cheat and get ITM to cut the panels to the correct dimensions (I don't have a tablesaw and my circular saw has seen much better days - more a grater these days than a saw :-)

Dave.

[jackinnj]

still use a Skil Saw for cutting panels -- the trick to acuracy is using an aluminum rule -- I have a device called "Strait Kut" which clamps to a 4X8 foot panel and the acuracy is excellent.

I sometimes cut smaller panels on my contractor saw -- I have a jig which fits in the grooves to push the panel acurately through the saw blade.

Here in the states, it depends on whom is doing the cutting at Home Depot -- a better investment is a decent circular saw, a 7 1/4 carbide tipped blade and the aforementioned jig.

[rolfy72]

If u need a straight edge to use as a guide, buy an extra sheet of MDF and use it as the straight edge!(only need 16mm tho)and take yer time cutting it using clamps to hold it...

[Dave Bullet]

Thanks for the responses. Because my circular saw is stuffed (centrepiece (or whatever is called) seems to be out of alignment) - it's good enough for outside timber work. Itseems a waste to buy a new one just for cutting a few pieces....

Besides - I'll take along a tape measure - and if the panels the hardware store cut are not square / accurate- I won't be paying for it (I'll leave the car running for a quick getaway

Dave.

[Philo]

Dave,
When you say "centerpiece", do you mean the notch on the sole plate that marks your blade or the sole itself? I never pay attention to the notch as they are usually inaccurate. The important thing to know is the distance from the edge of the sole plate to the plate on either side. Knowing both is the most versatile. If you use a straight edge like jackinnj described (or just buy an 8ft pice of aluminum from a quality metal shop) just measure the cut you want and add or subtract the distance described above depending on which side of the saw you refernce the cut from. If you precut a piece of hardboard that is width of blade distance and use it as a template. This makes for an easy setup.

[Philo]

One additional thing, if you predrill for screws use a smaller than normal bit for MDF, as in a #6 countersink bit for a #8 screw. Then use fine thread drywall screws. These screws hold up under distress better than coarse thread and MDF will strip out easily with either screw. If you really want to get fancy in the future, go with small head bugle deck screws from Mcfeely's. these don't require countersinking (just a little putty before you paint or veneer), use square drive and are very strong. No more snapped of heads.