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How to Seal, Varnish and Finish MDF and Seal all Edges?

Posted: Thu Aug 07, 2014 11:43 pm
by xcore
I have a little MDF project but now its about time to varnish it but not quite sure how to seal MDF properly; I have 2 pieces of scrap mdfs and sealed it with PVA glue mixed with water turns out okay I guess but it doesn't seems to fully seal the edges.

So the first sample, I varnished it already but few coats and sanded in between coats which turned out pretty okay and smooth but I don't quite like the feel of it when it gets warm because it feels a little rubbery. Was wondering how to properly finish a varnished project and remove the rubbery feel.

Re: How to Seal, Varnish and Finish MDF and Seal all Edges?

Posted: Wed Aug 13, 2014 1:01 pm
by thedoctor
PVA wont work on MDF edges before varnish very well. You can seal by adding water to a water based varnish and a little bit of white spirit to an oil based varnish to seal down.

The edges of MDF will never be the same colour as the surface I'mafraid. The end grain is exposed and will open wider to accepts more varnish/paibnt/oil etc.This always leads to a darker vinish when using a transparrent covering.

Get the best quality varnish you can and rub down very well between coats and you willachieve a top finish

Re: How to Seal, Varnish and Finish MDF and Seal all Edges?

Posted: Tue Nov 11, 2014 4:04 pm
by ChrisKia
I think you should deburr the surface and use body filler before varnishing!

Re: How to Seal, Varnish and Finish MDF and Seal all Edges?

Posted: Wed Nov 12, 2014 3:49 pm
by DIYDoctor2
We do have a project on painting and sealing MDF on the website https://www.diydoctor.org.uk/projects/mdf.htm