Humidity proofing MDF

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
...OK this is for my car stereo, but I am using Madisound purchased Vifa tweeters and midrange drivers and 8" Silver Flute woofers. I made adaptor plates for my doors and used MDF. However I am concerned that over time the humidity will cause the MDF to swell. What is the best way to seal the MDF so it can tolerate being used in a humid enviroment? Im thinking perhaps some type of a paint. I don't care what it looks like, I want it to work. Anybody recommend a specific product?

PS I searched and found a thread about sealing the MDF, but it was very concerned of how it looked. I don't care how it looks one way or the other, as the plates are hidden, but I do care about how effective the treatment is. Suggestions?
 
Use plywood instead of MDF if you believe water contact is possible. Plywood is stronger and lighter than MDF and it does not disintegrate when it gets wet. Using some deck water seal seems silly to me, but it might work. It also might interfere with any further paint or finish treatment you try. A nice coat of a good oil-based hard paint should be all the waterproofing it needs.
 
eric - I am imaging you are worried about it ending up like ordinary chipboard does? If you are using MDF - It is highly unlikely it will swell or disintegrate from humidity.

A good sealant - if you still want to do it - is glue. I use this to fill cut edges before sanding and painting and it works pretty well.

If I were you I wouldn;t even worry about it.
 
Go to a artist shop,and pick up the TRI-ART brand of "topcoat'. It is a undiluted acrylic-urethane. It takes time to cure, but the MDF will practically be submersible after that.

It is the same acrylic urethane that is used to finish BMW cars, for example. You are highly unlikely to find it cheaper..or better. best in the business. PS..it makes a helluva coating for finishing speakers, before painting, as well.
 
This may also help as a treatment prior to sealing.

Linky

I read about it on here, I haven't tried it but plan to on my next cabinets.

Bonda Wood Hardener

Wood Hardener is a moisture hardened one component resin for hardening rotten and decaying wood. Just think about it - all wood contains some moisture so a resin that actually uses moisture to harden has a distinct advantage over any system that does not. Wood Hardener is easily applied by brush, and penetrates deep into the fibres of the wood bonding them together to provide a solid matrix of wood fibres and resin. When cured the surface will be tough and hard, sealing the surface from further water penetration.
 
You can actually buy water resistant mdf aswell.. I used some for a bath panel in my last home.

Just for humidity I'd use wood glue mixed with water 50/50. (pva glue is also used to seal plaster and concrete in building apps..)

For proper water contact I'd use fibreglass resin.

In a car I wouldn't worry at all. (as long as the window rubbers are in good order etc...)

Rob.
 
eRiCdWoNg said:
...OK this is for my car stereo, but I am using Madisound purchased Vifa tweeters and midrange drivers and 8" Silver Flute woofers. I made adaptor plates for my doors and used MDF. However I am concerned that over time the humidity will cause the MDF to swell. What is the best way to seal the MDF so it can tolerate being used in a humid enviroment? Im thinking perhaps some type of a paint. I don't care what it looks like, I want it to work. Anybody recommend a specific product?

Moisture takes the most amount of time to penatrate aluminum paint (or any metical paint I suppose). Oils or polyurethane sealers, any wood products you can think of, would let moisture through at least 20 times faster.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.