Question on using MDF

[unclecritic]

I just read in an older mag that was given to me that it works really well to treat the edges and milled faces with a mixture of 2 parts yellow glue and 1 part water and it will seal it making painting easier.

I just recently built a few jigs that I actually drilled and tapped the pieces and used 10-32 machine screws... it actually worked really well.

Even nailing the stuff can be a little weird. I've had 3/4 mdf split from a 16ga trim nailer when I nailed it about 1 1/2 inches from the edge. Brad nailers from now on...

Whats the project if you dont mind me asking? I just got done refacing the vanity in the bathroom of the house that my "pretty much family" are trying to sell with 1/2" mdf and it turned out really well. I also learned that killz is a pretty good primer for mdf since thats what I had on hand.

I personally love the stuff

[RayintheUK]

The reason that some prefer to drill the pilot a little deeper is to do with a more uniform feel to the screwdriving. If the screw (of whatever type) has to find its way into some "full strength" MDF at the bottom of the hole, there will be a tendency to overdo the driving (when using power drivers) which - in turn - causes overtightening. In MDF, that results in the screwhole being rendered useless in many cases, as it's very easy to ream it out with the screw - much easier than in real wood, even plywood.

To overcome this, countersink first, do not rely on the screwhead to sink itself, because, as you can imagine, that adds to the force required right at the end of the screwdriving. For this reason alone, I tend to finish screwing very gently (stop it! ) and if I have any concerns when using thinner material, I finish tightening by hand.

The countersinking of the underside of the hole is a good thing to do whenever you can. If you can't, really firm clamping before piloting and screwing will overcome internal debris most of the time, IME.

Ray.

[Ed62]

How could I ask for anything more than this forum? Thanks for the replies.

Where are you from? I work in Griffith and live in Hobart, but grew up in Portage.

Brandon

I lived in Griffith for a number of years, but now we're in Cal Township. Glad to see we have another local.

Ed

[Ed62]

Ed - What's the project?
.

I'm thinking about a small router table, and a glue-up jig for picture frames.

Ed

[RodKirby]

Nothing I can add - all good advice.

BTW I ALWAYS countersink the back of the top piece (MDF and anything else)

[mclear6]

article on line

this is the article from shopnotes that I talked about earlier


It can be found on this website--- look for the working with MDF link in the right column

http://www.southpointhawaii.com/big_...er_builder.htm

[MilDoc]

The advantage to Confirmat screws is their straight shank and large flat head, but not really needed.

It is possible to get blowout along the length of the screw too if it is not pretty well centered. I avoid this by adding clamping pressure along the screw path where possible.