New build - Sealing the MDF?

[Bluemalu]

Hello All,

Just finished unpacking the Rostock MAX, all looks fine.

This is one of the newer versions without the melamine coating on the surface, the MDF isn't quiet as photogenic as the melamine.

My concern is moisture, is it worth sealing the parts first before building, I've waited over 3 months (being over the pond in the UK) to get the unit so a couple more weeks preparing aren't going to hurt.

Any advice greatly received.

Cheers

Drew

[cambo3d]

do you have a picture of this version mdf?

Measure all your vertical pieces to see if they are the same height, if not it will give you warping issues when you go to assemble it.

[mhackney]

I think I would seal raw MDF before building with a thin coat of varnish. I'm surprised they did not use melamine.

[Bluemalu]

The MDF is 6.0 mm thick, the only piece I have with the melamine on is 6.8 mm.

I suspect this has been cut in the UK to save shipping but as I'm new to this I'm only speculating.

I'm considering a mix of PVA and water delivered as a spray and then dried (I've access to a dehumidifier), I'll ask my supplier

http://creativemachines.co.uk/store/ind ... er=product

for an update tomorrow. - from their website the melamine has a health risk being cut...

Regards

Drew

[mhackney]

I thought the deal was that the cutting was being done in the UK to save shipping? Water on MDF is not a good mixture! It can swell very easily. Be careful and test on scrap.

[Bluemalu]

Therein lies the rub.

Paint would probably be too thick, same for varnish although it has the advantage that it can be thinned with oil / alcohol based liquids rather than water.

I've used PVA before to seal surfaces of MDF but as you rightly point out excess water and MDF are a really bad combination.

As I've said, not in a rush and I'll contact my supplier tomorrow.

[mhackney]

Yes, I was thinking aerosol can varnish, it is very thin. Or you could brush thinned varnish. It will actually absorb into the pores of the MDF and not leave a thick surface film. Just enough to get some humidity stability.

[JohnStack]

I wouldn't buy a kit that has uncoated surfaces.

[cambo3d]

for what its worth, i have a cnc router machine that use mdf as the bed and i've never had a problem with it. I also keep this machine in my garage where humidity changes often.

[mhackney]

My first CNC router I built a loooong time ago was MDF. I spray painted it and it was fine. No moisture or stability issues.

[Bluemalu]

Update: 30th March 2013

Started a build log. http://forum.seemecnc.com/viewtopic.php?f=42&t=1447

Spoken to Charl at creative machines, I considered changing to Acrylic but I didn't fancy the issues with heat and acrylic so I'm sticking with what I have and sealing it with Rustin's sealer.