MDF: What saw blade and screws to use?

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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
 
feke67 said:
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
 
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.
 
Dave Bullet said:
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
 
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.
 
I used a circular saw

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.
 
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.
 
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.
 
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.
 
Hi.

I always use polyerethane glue. It foams up, when the parts are moisted with a waterspray before gluing. (actually the moist in the air will do it too).
That approach makes all joints perfectly airtight.
Dont get the stuff on your fingers, (can be removed with paintthinner when wet) or you have to wear it of :=(

Kind regards Per
 
Per said:
Hi.

I always use polyerethane glue.


This is good glue, but it doesn't keep worth a dang. Once you open the bottle, it will harden in a week or so. This is the kind of glue that you don't buy that bigger bottle as it is only a little bit more and you think "I can always use that glue on my next project"! Nope. Plan on throwing what you don't promptly use away.

Unless someone has some tips on how to make it last longer... I have stored the bottle upside down, even, and it still hardened after a few days. Maybe humid Florida weather has something to do with it, I don't know.
 
Jeff R,
I had the same problem when I was in FL. Try squeezing the bottle until the air is out and the glue is right up at the top then cap it and store the bottle on its side. This will prolong the glue. Poly glue is good stuff but I switched to construction adhesive (HD Liquid Nails). It can be even messier to use but is very strong and is more reliable the poly glue to me. I have been able to pull apart some joints days later that had foamed to much and undermined the integrity of the glue.
 
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