Mdf vs. Baltic Birtch

[Acelectric]

A lot of the plans I find for various jigs recommend using Mdf plywood. It is very flat and stable. Somewhat cheaper as well. What I don't like about it is that all it takes is a little bit of water and it starts coming apart.

Is mdf that much more stable than Baltic birch? With all the layers it seems it should be pretty stable as well, although I have noticed it doesn't always stay flat.

What are you guys' opinions on the two ply-woods? Should I use mdf for all my jigs or would BB work just as well? Are there some things that I definitely need to use mdf, but others that BB will work just fine for, or maybe even be preferred?

 

[alachua1947]

I like Baltic birch because it seems to be moisture tolerant than MDF, and MDF sawdust can cause cancer, so I steer away from it.

 

[junquecol]

Generally my jigs don't get wet, so I use both, along with melamine covered MDF. Wish I could find a source of 1/2" melamine covered MDF.

 

[Weekendworrior]

My jigs don't get wet either but my gawd did they move and change with the humidy. I've used MDF, OSB, Plywood, and solid wood. OSB changed less but takes more work. The resin in MDF, OSB, and Plywood tears up your tools but I'm partial to OSB for jigs.

 

[Acelectric]

I never considered OSB for jigs. Do you use regular OSB or the kind made for sub-floors?

 

[Bill Clemmons]

I've used both 1/2" MDF and 1/2" BB for jigs, and both can work fine, depending on how they are used. Here are a couple of points to consider:

• BB is more expensive than MDF.

• If you are going to screw into the jig itself, then use BB. MDF does not hold screws well.

• If you are going to run a screw through the jig and thread it into something else, the MDF will be fine.

• If your shop is not climate controlled, and subject to wide fluctuations in humidity, then use BB.

• If you use MDF, it is a good idea to coat it w/ something, such as varnish, polyurethane, shellac, etc. to reduce moisture absorption.

HTH

Bill

 

[Pop Golden]

I agree with Bill. I will note MDF holds screws better through the surface than on end. I have used MDF for years. You better believe it's cheaper than BB. Have you priced BB lately? I think the dangers of MDF are a little overstated.

I don't understand the idea that OSB is better on your tools than MDF. The binder in both are very much the same. In some ways the waterproofing chemicals in OSB make it more of a health problem than MDF. OSB is a rough construction product. More prone to splinters, cracks etc. than MDF. MDF also takes finish very well, I'v never tried to put a finish material on OSB.

There you have it. I like MDF. I don't like OSB. But! AS has been said many times before, Each to his own taste.


Pop

 

[batk30msu]

Have you all ever tried the fasterners that are designed specifically for MDF? http://img.diynetwork.com/DIY/2011/02/23/RX-DK-DIY076037_mdf-screws_s4x3_lg.jpg

I tried them and I found they hold quite a bit better than drywall screws or other options.

 

[SubGuy]

Advantech OSB is a much better OSB for movement prevention and moisture resistance. As far as how hard it is on tools, as long as you making jigs you have little exposure to it compared with the project wood itself. So, you shouldn't dull bits or blades and you should have minimal exposure to the dust. With normal use of a efficient dust collection system, you should have little to no exposure to dust. Dust is also less fine than MDF. I like OSB for stability, however....BB generally has less frequent and small thickness variations. Pick your poison or make all your jigs from aluminum or some poly based material. Hope you have an expanding wallet for those.

 

[cyclopentadiene]

Baltic birch is the best material for indoor skateparks with no finish. It is very fast, not slick (unless finished) and provides very little movement. it is also dutable and does not produce dust like masonite. Skatelite(made from recycled plastic bags) is $200 per 4 x 8 sheet so baltic birch is much less expensive. Not related to woodworking but as you ca see from my avatar, I am a skateboarder as wekk as woodworker. I thought some may enjoy some uses besides woodworking.

 

[Acelectric]

Thanks for all the replies. :icon_thum

I guess most of my resistance to Mdf comes from so many years of doing woodworking out in the yard. You never knew when it might decide to rain.

Since buying my new house I have a small but serviceable shop in which to work. I may give Mdf another look, and maybe the Advantec as well.

Thanks again for all the advice.

 

[Weekendworrior]

I don't understand the idea that OSB is better on your tools than MDF.

For clarity, I didn't mean to indicate that OSB was in anyway better on tools. I was stating the resins in all fabricated lumber/building materials is hard on blades.