White painted kitchen cabinets

[Cooler]

I will be replacing my kitchen cabinets with shop built ones shortly.

I've made many cabinets, but always stained and clear coated hardwood.

This time I am making Shaker style cabinets painted white.

I was in Lowes the other day and they have several cabinet styles on display (not the ones that are in cartons for carry out, the ones you order to spec.).

They seem like pretty good cabinets with Blum soft-close hardware and 3/4" through dovetail drawers aand all plywood construction.  Not top of the line, but pretty good specs.

But their painted cabinets all seemed to have a micro-fracture of the paint surface at the junction of the rail and stile joint.  I examined the joints and it is a standard 1/2" stub tenon.  The fracture shows up as a dark thing line where the paint fractured.

I would be very upset if my cabinets show the same flaw.  What can I do to ensure against this?  Obviously there is some flexing of the door joints to  make the finish crack like that.  Perhaps adding two dowels to the stub tenon.  That would be pretty easy to do (but time consuming).  

Any thoughts?

[hbmcc]

I have 30 year old cabinets, not painted but solid with no strain at frame joints. These cabinets have deep (7/8") frame slots for a substantial expansion gap; and joint. A second, newer set of cabinets have 1/2" deep slots. The expansion gaps could not hold the rubber footballs. There was joint and wood failure in two doors. Both sets use oak. 

I think, the closer you can get to a true mortise and tenon, the better. A 1/2" f & p is OK, but find deeper for the frames. And, can you let the wood sit for about a year? You will need plenty of time for paint to cure, also.

[Cooler]

I always let my finishes cure for 200 hours before use.  

In the past I made the rails and stiles with my dado head and used 3/4" stub tenons.  This time I am cutting these on the router with matched tongue and groove set and that tenon is just 1/2".

I think I will add two dowels to keep everything tight.

I store my materials in the basement which is noticeably more humid than the mail living areas.  I just checked a cabinet that I built 18 years ago and the poly finish it intact with no fractures at the joint lines.

Do you think this is from seasonal wood movement or from flexing of the joints?

[rwe2156]

I've had this happen to me.  I think its more prevalent in wide doors probably due to flexing.

I've been able to come up with a few explanations: dramatic temp changes during glue curing where the glue wants to shrink before its completely dry, inferior paint/finishing technique, faulty joinery last but not least, improper panel installation (too tight) which can push a joint apart if it expands.

I really think it has a lot to do with the paint.  I'm ceraintly no expert but FWIW I go with all oil based paints on cabinets.  BIN shellac based primer and SW ProClassic top coat.

[Cooler]

I don't think it was panel shrinking or expanding.  It was a Shaker type cabinet and those fields are made from plywood.  

This is going to be my first real project spraying so I'm no expert in that field (I usually just read the directions on the can).

I was planning on using PPG Breakthrough.  It's gotten some good reviews.

Maybe I will make one cabinet as a test and use it for a while before I proceed.  I've got my carcass construction down pat.  I really thought this whole project would be a no-brainer until I saw the paint fractures.

[Stwood_]

I would say those Lowes cab probably had a gap on the joint, for the paint to be not covered there.
Paint probably absorbed into the joint.

[jteneyck]

I just read about this on another site frequented by mostly pros.  Many said this is usually caused by not waiting long enough for the glue joint to dry before painting.  Of course that makes no sense to a hobbiest because not many of us are spraying the same day we build the faceframe, door, etc., but some pros do and probably most factories do.  If they are right you shouldn't have a problem.  If you want to add dowels or make deeper stub tenons they won't hurt, to be sure, but letting the glue dry before painting is more important.  

I also think the width of the stile/rail joint, the type of wood and grain orientation, the RH changes during the year, and the elasticity of the finish you use all play a role in this issue.  

John

[Cooler]

I just read about this on another site frequented by mostly pros.  Many said this is usually caused by not waiting long enough for the glue joint to dry before painting.  Of course that makes no sense to a hobbiest because not many of us are spraying the same day we build the faceframe, door, etc., but some pros do and probably most factories do.  If they are right you shouldn't have a problem.  If you want to add dowels or make deeper stub tenons they won't hurt, to be sure, but letting the glue dry before painting is more important.  

I also think the width of the stile/rail joint, the type of wood and grain orientation, the RH changes during the year, and the elasticity of the finish you use all play a role in this issue.  

John

That was me again at the other site.  I am going with their recommendations on waiting.  I always have a little squeeze-out so I'm sure I am not starving the joint for glue.

I'm making shaker cabinets so the panel is plywood and will not cause expansion issues.