Bathroom vanity doors.

[lambeater]

About to start building doors for my VG fir bathroom vanity. Managed to locate a nice flat sheet of VG fir over mdf for a good price. Should I have any concerns about this for the doors, except edging and sealing up all six sides to lock out moisture? Bathroom fan is always on when moisture present and is 150cfm so I wouldn't expect any issues. Any thoughts welcome.
thx
Lambeater

 

[Rob-GB]

Hi Lambeater,  [big grin] first a question...what is VG fir?  [embarassed]
That aside I am assuming its a veneered mdf board and the policy is pretty much the same for all. The panel size for the doors remain more stable the smaller they are and the better they are lipped/ edged( moisture resistant glue) then sealed with a finish that will keep moisture out. Any door greater than 1 mtr (39") high ought to have a pair and a half of hinges, this is a major rule in the workshop I work and from long experience.  [wink]
Veneered boards are often used in bespoke cabinetry for humid areas,generally with few problems, there is a school of thought that recommends sealing any hinge sinkings (euro hinge style or conventional butt hinge type).
Don't forget to post the finished project ;D
Rob.

 

[lambeater]

Hi Lambeater,  [big grin] first a question...what is VG fir?  [embarassed]
That aside I am assuming its a veneered mdf board and the policy is pretty much the same for all. The panel size for the doors remain more stable the smaller they are and the better they are lipped/ edged( moisture resistant glue) then sealed with a finish that will keep moisture out. Any door greater than 1 mtr (39") high ought to have a pair and a half of hinges, this is a major rule in the workshop I work and from long experience.  [wink]
Veneered boards are often used in bespoke cabinetry for humid areas,generally with few problems, there is a school of thought that recommends sealing any hinge sinkings (euro hinge style or conventional butt hinge type).
Don't forget to post the finished project ;D
Rob.

Sorry Rob VG fir is Vertical grain douglas fir. Doors are regular sized cabinet doors. Kamloops here in British columbia is very dry with low humidity.
thx
Lambeater

 

[Kev]

I've only every had misery where MDF and moisture can come together ... for that reason I'd never risk what you may be about to do.

It swells, it warps and it deteriorates ...

Whatever you plan to seal it with ... test sealing a piece of MDF with it and stick it in a bucket of water for a week before you consider it "good enough".

 

[Rob-GB]

I've only every had misery where MDF and moisture can come together ... for that reason I'd never risk what you may be about to do.

It swells, it warps and it deteriorates ...

Whatever you plan to seal it with ... test sealing a piece of MDF with it and stick it in a bucket of water for a week before you consider it "good enough".

The only real problems occur is when veneered mdf is routed or not edged/lipped thus leaving just the finish (varnish/oil or two pack) protecting the mdf core.
Anytime the finish gets knicked or chipped can allow ingress of moisture. Solid wood sucks moisture in more readily through end grain, not so fast with face and side,
due to the wood cells design; mdf consists of pulped wood fibres and those little suckers (pun intended) act like a sponge, especially noticeable at board edges.
If the edges of the doors are to be routed with a decorative detail then the lipping material ought to be a few (3mm+) greater than the detail.
One of the worst things, both in looks and practice, is to route a faux panel into veneered board.

Rob