Hairline Cracks on Painted Cabinet Doors and Drawers

Natural wood movement will inevitably show up through a painted finish at wood joints. August 19, 2008

I need advice. Last July/August, I installed a kitchen (residential) with paint grade maple flat panel stile and rail doors and drawer fronts. A couple of weeks ago the GC called and told me the customer informed him that the joints on the stile and rails had hairline cracks on about 50% of them.

This past week I visited the project and also observed the hairline cracks on the doors and drawer fronts. The joints are still secure, they just have hairline cracks. Additionally, one of the upper end panels that I had assembled myself with 4 wide stiles and rails out of maple with biscuit joinery had a crack that was next to the joint.

The door specs called for the stile and rails to be x 4 wide net instead of the standard 2 and were purchased from a reputable cabinet door manufacturer in the Fort Worth, TX area. Our local hardwood dealers say that the hardwoods are dried to around 8-12% moisture content. The paint finish was 2 coats of white lacquer under-coater with 2 coats of a top-of-the-line white gloss lacquer. The doors were painted within a week after I received them and installed a week or two later.

When I visited the project, the customer told me that they have a humidifier that they keep at 42-45%. What should I do in this situation? My concern is if I fill the cracks and repaint the doors, the expansion and contraction may continue with the Texas climate, and this will occur again.

Forum Responses
(Cabinetmaking Forum)
From contributor B:
That's the way it is. Wood moves, so you can temporarily fix it, but it will crack again. I think the only way to avoid it is getting the foil doors.

From contributor T:
That is why I use one piece MDF doors for paint grade or I give a disclosure to the clients about the wood movement. You don't see the cracks in stain work, only in paint.

From contributor J:
They will have cracks on painted cabinets. They are, after all, a wood product, and as such, they expand and contract. Only way is to go one-piece MDF or Thermfoil. They're not cracked, it's just natural movement, that will, by the way, continue. I would stress that, and attempt to move on. Tell them you were surprised how long it took, as they should have shown up sooner, but the other 50% will catch up. Option C is plastic cabinets.

From contributor K:
I agree that the wood will move, but some white color putty may make them happy.

From contributor C:
The above advice is right on the money. I sell cabinets for several national manufacturers. The ones that manufacture painted cabinets and doors require the client who is buying the kitchen to sign an acknowledgement. We, in turn, have to provide a copy to the manufacturer before they will even take the order. The acknowledgement states hairline cracks are part of the natural process of solid wood movement and therefore any hairline cracks that may develop are not considered a defect, and therefore are not warrantable. If you would like a copy, email me, and I will fax it to you.

I know it is a little after the fact, but it might help if a copy of this is shown to the client. I would advise anyone who paints solid wood cabinet doors to add this little piece of paperwork (signed by client) to every painted cabinet sales order.

About 15 years ago a very large cabinet company in the Northwest went bankrupt trying to warrant this very issue. The only crack free painted doors I can guarantee are the square corner MDF raised panel doors I make on my CNC.

From contributor D:
When you go to look at job and explain what everyone else has said here, take them to other cabinets in their house that have natural finish (or stain) that have grain showing. Get them to run their finger over the joints at the rails and stiles and they will feel the crack. Wood grain hides a lot of cracks and blemishes. Because of this I up charge for sprayed painted finishes due to prep time.

From contributor O:
To address this problem I make my 5 piece shaker style doors with 19mm ash veneered MDF for the frame and 6mm for the panel. These then get painted and I have never had a crack. It's because there is no differential movement due to there being no grain, but you can clearly see the wood grain (of the veneer) through the paint. Works great and looks good.

From contributor M:
I find that the door and drawer companies typically do not put enough glue on the joints to prevent this cracking. Obviously when gluing clear finish woods, you don't want to see any glue marks.

However, when we build our own paint grade doors, we apply plenty of glue and virtually never have any cracking problems at the stile/rail joint. It is typical to have cracking at the panel/frame joint.

However, this can also be almost completely eliminated by gluing an MDF panel into the frame. I am not blaming the door and drawer companies, but only gluing the tenons will result in surface cracking.

From contributor N:
Most door and drawer companies doors don't have tenons, only cope and stick joints. Not much good glue surface there since it's mostly end grain on the rails. Same argument goes for putting glue anywhere but on the tenon and in the mortise.

From contributor M:
The cope cut produces a tenon. An end grain/side grain glue joint is quite strong. Test one.

From contributor N:
I wouldn't call that little stub on the cope a tenon. It's not nearly as strong as the
1 1/2" long tenon that's on the doors I make. I've tested plenty of those.