2nd attempt at cope and stick

[stephen wood]

I've made two cope and stick doors for a bathroom vanity. They had 1/4 plywood panels.
This time I'd like to have a raised panel on two doors 15" x 22".
They will be painted white so I'm thinking of using MDF for the panel to avoid wood movement issues. I believe this would also increase door rigidity. What do folks think of this?

I seem to recall reading about sealing the mdf before painting.

[Joe Jensen]

MDF Will not move so you can size it to fit perfectly and it can be glued in the slots. If you panel raise the MDF read about sealing the cut edges before paint. I've read about many solutions. One is watered down glue brushed on, another is shellac, another drywall compound. If you don't seal, the cut edge will absorb a ton of paint and it will "grain raise" a ton of fuzz.

[Jim Becker]

It's very common to use MDF for panels in doors. It doesn't move as has been noted and can be machined nicely for things like raised panels. There is some work smoothing and sealing those cut edges, but it's almost the perfect material for a painted situation. Be sure you use good dust control and PPE while machining it...the fine dust is, um...prodigious. :)

[stephen wood]

Thank you for confirming my approach and the caution about dust.

[Richard Coers]

MDF does move, typically around .3% from a humidity change from 30-90% for length and width and 5% in thickness from 30-90%. How well do you ventilate the bathroom during a shower? Kids use the vanity? If you do use MDF, prime and finish the edges before assembly.

[stephen wood]

MDF does move, typically around .3% from a humidity change from 30-90% for length and width and 5% in thickness from 30-90%. How well do you ventilate the bathroom during a shower? Kids use the vanity? If you do use MDF, prime and finish the edges before assembly.

My first two doors will be in a regular setting--no bathroom humidity issues.
But within the next month I'll be building another bathroom vanity and would like to have raised panels, so humidity comes into play. There will be an exhaust fan in use when showering. Empty nesters so no kids living here, but occasional use by grandchildren.

[Jim Becker]

You do have the option of purchasing exterior grade MDF for your application. It's a little heavier and pricier, but is less prone to moisture issues. However, unless folks are "truly messy" people who also damage the finish, regular MDF properly sealed should probably work fine. A lot of commercial painted doors are made from MDF.

[John TenEyck]

MDF does move, typically around .3% from a humidity change from 30-90% for length and width and 5% in thickness from 30-90%. How well do you ventilate the bathroom during a shower? Kids use the vanity? If you do use MDF, prime and finish the edges before assembly.

That's a non-issue for finished panels in a typical bath. It would be a concern if MDF were left in a steam room continuously, but that's not the case in any normal bathroom. My bath vanity and storage cabinet have hardwood edged then veneered MDF doors and drawer fronts. Five or six years later they are as flat and stable as the day I installed them.

John

[Aaron Rosenthal]

This is MY OPINION ONLY, but I've remodelled houses for years before "retirement" and I only agree with one proviso listed here - Exterior grade.
There is no way to protect against moisture in a bathroom, and once there is any dampness, MDF will deform. Been there and done that.
For baseboards, for example, I always specified finger joint or solid, depending on the budget; for cabinets, plywood.
Now, it depends on the time frame. If your projected time span is 5 years, MDF may be an option. For anything longer, even raised panels, I would look closely at solid wood and know you're protected.
I don't know where you live, but I worked both in high humidity and West coastal areas, and my suggestion remains the same.

[Richard Coers]

That's a non-issue for finished panels in a typical bath. It would be a concern if MDF were left in a steam room continuously, but that's not the case in any normal bathroom. My bath vanity and storage cabinet have hardwood edged then veneered MDF doors and drawer fronts. Five or six years later they are as flat and stable as the day I installed them.

John
You haven't met my wife. She's really cold blooded and refuses to run the exhaust fan while showering in the winter. We'll be married 48 years this month, I don't think she will change soon. She turns the fan on when she leaves the bathroom. Every surface in the bathroom has condensation on it. I find it highly unlikely she is the only person that does that.

[Jim Dwight]

I've changed out all the molding in my house. I used mainly MDF baseboard because it is cheaper and I think the shape is more consistent which helps with copes. But in the bathrooms, I used only finger jointed material. But baseboard sits on the tile floor so it is more likely to get wet. It is at least primed, but...

I think MDF will work for panels but I detest working with it so I wouldn't do it. There is some risk it won't get protected by finish and fall apart but I think that risk is low. I used a lot of it when I was making shutters for my last house and it painted up well - with a good primer on it and extra sanding and finish. I routed the louvers and made most of them out of MDF. So I know it can work. But I would prefer to use something else. Wood is just much nicer to work with. You have to allow a bit of room for it to move and I finish the panels before glue up so I do not have unfinished lines on the panel if it shrinks. Strength should not be an issue. I built an entire kitchen with raised panel oak doors. Panels were 3/4 thick oak. Doors were up to at least 18 inches wide. Joints were little router table cope and stick. No issues at all. If your doors are smaller and your panels lighter (like pine or poplar) you would have even more margin.

[Derek Cohen]

This is MY OPINION ONLY, but I've remodelled houses for years before "retirement" and I only agree with one proviso listed here - Exterior grade.
There is no way to protect against moisture in a bathroom, and once there is any dampness, MDF will deform. Been there and done that.
For baseboards, for example, I always specified finger joint or solid, depending on the budget; for cabinets, plywood.
Now, it depends on the time frame. If your projected time span is 5 years, MDF may be an option. For anything longer, even raised panels, I would look closely at solid wood and know you're protected.
I don't know where you live, but I worked both in high humidity and West coastal areas, and my suggestion remains the same.

Aaron, I am personally interested in your reply as I am planning on building new doors in Hard Maple for cabinets in two bathrooms. The style is Shaker frame-and-panel, replicating the work I did in our kitchen ...

https://i.postimg.cc/1z8Zfvjc/E2-F80-A1-A-B3-FA-49-F0-973-E-BF141-DA0-F920.png

The question is whether the panel is made from veneered MDF, veneered ply, or solid wood. My initial thought was to veneer, but there is the concern that moisture will affect the veneer, plus it is a lot more work to do than using solid wood. The choice is narrowed to solid wood panels, which is what I did in the kitchen, and now the decision is what internal gap is ideal for Hard Maple to expand? Any thoughts on that?

Regards from Perth

Derek

[John TenEyck]

You haven't met my wife. She's really cold blooded and refuses to run the exhaust fan while showering in the winter. We'll be married 48 years this month, I don't think she will change soon. She turns the fan on when she leaves the bathroom. Every surface in the bathroom has condensation on it. I find it highly unlikely she is the only person that does that.

You're absolutely right Richard. After almost 48 years together your wife is unlikely to change her habits. Mine hasn't after 40, though I foolishly keep hoping.

John

[stephen wood]

Thanks for your comments Jim. I’ll consider wood panels.

[Steve Rozmiarek]

My opinion of raw MDF raised panels is pretty poor. By the time you mill, then fix the cuts so they won't react horribly to paint, you could have easily just used a piece of solid poplar and been done with it. Every now and then I test that theory and try some painted MDF again, and always come back to the poplar. Plus poplar is lighter, stronger and pretty easy to find in normal cabinet panel widths so you don't have to glue up to make wider stock.

[stephen wood]

My opinion of raw MDF raised panels is pretty poor. By the time you mill, then fix the cuts so they won't react horribly to paint, you could have easily just used a piece of solid poplar and been done with it. Every now and then I test that theory and try some painted MDF again, and always come back to the poplar. Plus poplar is lighter, stronger and pretty easy to find in normal cabinet panel widths so you don't have to glue up to make wider stock.

I can see the appeal of using poplar. I have a good source of that nearby so I'll give it a shot. I am sensitive to dust so I wasn't looking forward to MDF in that regard. So do folks just use spaceballs to manage panel movement? never done it before.

[Aaron Rosenthal]

Derek, I have experience in not only Canada (Vancouver, lower humidity but LOTS of moisture from annual rainfall), but also in a very high humidity environment in Israel.
Renovations (remodelling for American speakers) in bathrooms in Vancouver were almost always spec'd for solid or finger joint material, baseboards especially. Yes, the commercial cabinets are made from faced particleboard, even worse than MDF, but I always asked about the proposed life span of the renovation and/or ownership of the house. If short term, I went the cheaper way (excepting baseboards, that was non-negotiable) with wood substitute. Longer term, wood.
Most people upgrading their home have a plan for a sauna or steam shower, or, they have children (not baby goats) who splash in younger years and take loooong hot showers as teens. That calls for wood, because one imperfection in the finish including the Eurio hinges are a moisture ingress.
In Israel, the kitchen and bathroom areas are not subject to localized moisture (it IS desert country where I was) except in the kitchens, but in the Sharon valley it had high natural humidity and the winters were wet and dreary. After 20+ years the original cabinets were more puffy than my face after a 3 hour night sleep, so I insisted on faced plywood. Now, with universal A/C in place, that environmental humidity may be altered enough to keep the cabinet sides and doors good for another 20 years, but, for resale value anywhere unless flipping, why take the chance for what essentially is a few dollars.

[Derek Cohen]

Thanks so much Aaron. Perth is similar, I suspect, to other desert conditions, where the air is dry in summer, and the summers are long. However, this likely makes the moist conditions of a bathroom more of a threat.

Allowing for movement of the panels in their frames is going to be critical. I got it right with 95% of the doors in the hard maple kitchen, but a couple became gappy, and I had to pull them apart to deepen the groove for the panels. This was possible as I made the solid panels 1/4” throughout, and they simply slid into 20mm thick frames. I guess that I am answering my own question now - just make the grooves deeper. :)

Regards from Perth

Derek

[Steve Rozmiarek]

I can see the appeal of using poplar. I have a good source of that nearby so I'll give it a shot. I am sensitive to dust so I wasn't looking forward to MDF in that regard. So do folks just use spaceballs to manage panel movement? never done it before.

Spaceballs work fine, other more creative materials also work. Used some pool floater foam one time because I was in a pinch, it's still working fine. Recommend finishing the panels before assembly if possible, then you don't have to worry about a paint line showing if something shrinks.

[Warren Lake]

space balls made no sense to me, I used 1/4" naughyde car roof padding from upholstery shops. Slices with a knife simple and easy whatever width you want. Your panel should be pinned in the center anyway. I cut the width I want as im doing it, it has way more compression there is always a bit of pressure on the panel edges.

[Tom M King]

I took apart an original entry door on an 1850 house, because the 15" wide single board panel was showing a crack on one side, and it had so much paint on the outside that it needed to come apart anyway to clean it up. That panel had Beaver fur packed all around the panel. Someone in the 20th Century had pinned it, but the pin was on one side, and that caused the crack problem. I'm not sure if the Beaver fur was originally felted, or poorly felted, but it was all in there with the hairs all perfectly aligned in the same direction.