Finish sanding veneered MDF

UKworkshop.co.uk

Help Support UKworkshop.co.uk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

rkchapman

Established Member
Joined
22 Mar 2007
Messages
85
Reaction score
4
Location
Worcestershire
Long-time lurker here, needing some advice.

I'm building a bed out of (mostly) walnut veneered MDF (with some solid walnut), and wondering what the process for finishing it is. Searching for advice on finishing walnut leads me to think that either Osmo PolyX or some variant of finishing oil is probably going to be the way to go (I will try both on some test pieces) - but also general advice is to sand to 220 grit first.

What I'm wondering is whether that sanding advice applies to veneered board too (I'm worried about sanding through the veneer, it's not very thick!)

Any advice?
 
I've just been doing something very similar with Oak veneered MDF this week.

I didn't bother sanding it at all first, I just got a coat of Osmo on it once the parts were cut out. This was really just to protect them from mucky finger prints or errant glue spots but it worked out fine.

Then I gave it a light going over with 320 on my RO to knock down any burrs or raised fibres before giving it another coat.

This was for drawer boxes in a single divan bed I'm building (check out my IG page for photos). Once I've completed the rest of the finishing I'll give all the oak parts a final light sanding with 320 and another coat of Osmo.

Will
 
I did similar to Will recently but with Sapele veneer wardrobes. I sanded to P180 initially, then de-nibbed with P320 after the first coat, then a second coat and job done. I used Osmo Polyx clear satin, came up a treat.

Was the subject of a couple of recent videos, link in the sig.
 
Thanks all - sounds like Osmo gets the vote of confidence! I'll try on a few scraps first to see how much sanding is enough (and how much is too much!)
 
One more question, if I may - if building wardrobe carcasses from veneered MDF, do I need to finish both sides, or just the faces that will be on display? What about faces that will be resting on other carcasses?
 
Yes, you definitely need to apply some finish to the non visible sides as well as the visible sides.
If you are looking to save some money it doesn't have to be Osmo, basic cheap danish oil from Toolstation will be fine.
 
Osmo is probably the best and easiest to work with, unless your spraying it, rag it on, wipe off, leave it till next day, quick denib with p320, repeat process, may need 3 coats, secret with osmo apply thin coats so it can dry properly.
 
I have been using a velour roller for applying the first coat of Osmo to the veneered MDF.
This puts quite a large amount of oil on but if you've got two or even three panels on the bench at the same time you just work between them applying and mopping up the excess with the roller. Gets the job done very quickly.

I use a 2" brush for the second coat and apply it thinly, working with the grain.

I have only done two coats for my wardrobe internals with an overnight drying spell and a denib with 320 between coats. The heavier first coat fills a lot of the open grain and then the thinner second coat gives it a nice smooth finish.

The finished result is perfectly acceptable for a fairly expensive bespoke wardrobe. If it was a dining room table top it would probably get another coat or two though.
 
Back
Top