Thread: MDF, Bunnings Plywood or Birch Ply for Jigs

MDF is extremely stable PROVIDED you keep it away from moisture. I usually coat my templates etc with thinned-down matt varnish; five or six years ago I made a batch of zero-clearance inserts for my chop saw and stored them on a shelf in the shed. Last weekend I finally got around to replacing the one I fitted at that time; not a single one had swollen or feathered.

Another tip would be to round off all corners or apply an edging to any edges that must have 90 degree corners or are subject to wear.

I predominantly use 18 mm MDF for jigs. It’s low cost, readily available and very stable.

Bunnings ply really isn’t that great, and I’ve yet to find birch ply at a reasonable cost so would never consider using it for workshop jigs.

I also use the micro-jig DT clamps, and they hold without an issue in MDF sleds and jigs.

Originally Posted by LanceC

I predominantly use 18 mm MDF for jigs. It’s low cost, readily available and very stable.

Bunnings ply really isn’t that great, and I’ve yet to find birch ply at a reasonable cost so would never consider using it for workshop jigs.

I also use the micro-jig DT clamps, and they hold without an issue in MDF sleds and jigs.

Thanks for the reply mate. Do you think MDF is more stable than birch ply?. I agree about the birch ply prices, they're crazy.

MDF is dimensionally more stable. All my jigs are also made with MDF, one of which uses the DT clamps without any structural problems. I generally add some wax for protection. I have used marine ply on some things but for jigs MDF is much cheaper and works better and don't forget to use a dust mask, that's its only drawback.

Originally Posted by EagerBeaver71

Thanks for the reply mate. Do you think MDF is more stable than birch ply?. I agree about the birch ply prices, they're crazy.

I don’t know if it’s more stable, but as a manufactured product, is extremely stable.

I’m guessing you’re asking about birch ply because that’s what we see the Americans using on YT. If so, don’t fall into the trap of thinking that it must be better. I put it down to a different geographic region with different cost structures which makes it a viable option for them.

I would suggest you just go out and buy a 2400x1200 sheet of MDF ($40 ish) and make some sleds and jigs. That will get you over your analysis paralysis.

I have ordered a sheet of 16mm Valchromat through Bunnings to make jigs, etc.

Originally Posted by barri

MDF is dimensionally more stable. All my jigs are also made with MDF, one of which uses the DT clamps without any structural problems. I generally add some wax for protection. I have used marine ply on some things but for jigs MDF is much cheaper and works better and don't forget to use a dust mask, that's its only drawback.

Thanks for the post Barri, You must have read my mind because I was going to ask what do all you folks use to seal the MDF with. Considering I'm using the dovetail system I imagine it has to be a thin layer of something. Paste wax seems to be a good choice like you said, can I use anything else maybe?.

Originally Posted by LanceC

I don’t know if it’s more stable, but as a manufactured product, is extremely stable.

I’m guessing you’re asking about birch ply because that’s what we see the Americans using on YT. If so, don’t fall into the trap of thinking that it must be better. I put it down to a different geographic region with different cost structures which makes it a viable option for them.


I would suggest you just go out and buy a 2400x1200 sheet of MDF ($40 ish) and make some sleds and jigs. That will get you over your analysis paralysis.

Totally bang on Lance!, watching all the YT video's which seem to be American made me think ply is the way to go!. Excellent advice and exactly what I needed, I do over think things!

What are my options for sealing the MDF mate?.

Originally Posted by Bucky

I have ordered a sheet of 16mm Valchromat through Bunnings to make jigs, etc.

G'day Bucky,

Whats Valchromat?, is it that furry stuff?

Originally Posted by EagerBeaver71

What are my options for sealing the MDF?

Cheap or leftover varnish; matt, but not water based. Dilute it with the appropriate thinners for the product; 10-20% should be enough to ensure it gets really runny and soaks in and dries quickly. But as I posted before either round off all sharp edges or cover them with edging strips; either solid timber or iron-on melamine.

Originally Posted by EagerBeaver71

G'day Bucky,

Whats Valchromat?, is it that furry stuff?

I had to look this stuff up - seems like a great alternative to MDF. Manufactured/similar to MDF, but pine fibres and mill waste, and coloured with 'organic' colourings. Water resistant, and can be sealed with water-based varnish (sprayed for easy application). And can be recycled as biomass fuel.

It doesn't come up in a search on the Big Green Shed's website, so local source may need to be found?

Originally Posted by Bernmc

I had to look this stuff up - seems like a great alternative to MDF. Manufactured/similar to MDF, but pine fibres and mill waste, and coloured with 'organic' colourings. Water resistant, and can be sealed with water-based varnish (sprayed for easy application). And can be recycled as biomass fuel.

It doesn't come up in a search on the Big Green Shed's website, so local source may need to be found?

It’s not on Bunnings website. You order through the trade desk. It’s also not cheap.

Originally Posted by Bucky

It’s not on Bunnings website. You order through the trade desk. It’s also not cheap.

This stuff sounds incredible Bucky, how did you come across it, have you used it before?. I'm still reading about it but apparently its going to eventually replace MDF and the likes.

So many creative people on here, that's why the Australian Woodwork Forum is my number one goto for advice. Thanks to all you fine gentlemen for replying to my post as usual.