[blackte]

I built some custom cabinets for a client of mine, that are housing Audio/Video equipment in one cabinet, and a computer tower in another cabinet. There are three cabinets, all have a 12" x 12" opening in them to allow cables and air flow. Each outside cabinet has a powder coated wire panel(reliable hardware) installed in it. When I originally talked with the clients I told them that they would need some sort of small fan inside the cabinets to help move the hot air from the equipment out, or it would cause problems with the cabinets and doors. I got a call today from them telling me that the doors on the two cabinets had bowed out in the center. Obviously I asked about the fans and they are not in the cabinets.

Cabinet specs - Each cabinet is built with 3/4" Combi Core Poplar plywood, each door is built from strips of poplar, 1 1/2" wide glued together. Cabinets and Doors are sprayed with two coats of Primer, and two coats of Oil paint.

Attached is a picture of the cabinets that I'm talking about. Have you ever encountered this problem before. From my end, it's the heat that is causing the doors to bow out. The third cabinet with two drawers in it, and no equipment is just fine. Also along with this project, are 7 other cabinets, built the exact same way, with no equipment in them, and they are just fine also.

I have been building cabinets for many years, and have not seen this issue before. Has anyone dealth with this before.

Give me your thoughts on this. Thanks in advance for any help you can provide.

 

[The Coastal Craftsman]

I would install a couple of 200mm PC exhaust fan in the top corners on the back of the cabinet. That will move a lot of the hot air. I have 3 of them inside a PC case and its stays super cool.

 

[Gus Dering]

Those slab doors are made with solid poplar?

If I read that right, I would take issue with that choice. Why would you not use sheet goods for that?

 

[blackte]

Those slab doors are made with solid poplar?

If I read that right, I would take issue with that choice. Why would you not use sheet goods for that?

As like most small shops I don't have access to a good edgebander. I do have a hot air bander, but I would not trust it with something like this. I have looked around to rent, nothing. If I had a way, I would have went that route, would have save me time, money, headaches and the such. Still looking for a used one.

 

[PrestigeR&D]

1-1/2" poplar glued together ,...expansion / contraction....to much movement going on within each door. May want to use ply and iron on banding/- birch ,,,,




JMPOV,



B,

 

[openhearth]

I would say heat is definitely your issue. This is a pictures of some built-ins I did a year or so ago. They have all of their audio equipment in there so I told them I would have to include a fan with a built-in thermostat. I just screwed it into the inside top of the cabinet.

 

[openhearth]

Here is the site I used for the fan and mounting kit
http://www.hometheatercooling.com/purchase.html

 

[Kent Whitten]

Why would you not use sheet goods for that?

That was my first thought as well.

As like most small shops I don't have access to a good edgebander.

You don't need an edge bander to edge band 3 doors. Get an iron out and just do it. It takes 10 minutes.

Have you thought about MDF doors with a 1/4" (or whatever) glued on piece on the edges? It would stay flat and be durable. It's about as cheap a door as one can make.

 

[blackte]

That was my first thought as well.



You don't need an edge bander to edge band 3 doors. Get an iron out and just do it. It takes 10 minutes.

Have you thought about MDF doors with a 1/4" (or whatever) glued on piece on the edges? It would stay flat and be durable. It's about as cheap a door as one can make.

With this project there are 10 doors total. I have tried the iron on process, with some success. I have a hot air bander, and the same with it, some success. I just don't want that call that the edge banding is coming off.

I never throught about using MDF for the doors. I have done glue ups before and not had any issues with them, so I continued that same tradition with these doors. I guess I need to rethink my door process in the future.

I still think that the amount of heat that is being trapped would cause any door to warp or bow, no matter what it is made of.

 

[Kent Whitten]

I will agree with the heat trapping part. The edge banding...something is wrong there. Either you are getting bad edge banding or you aren't taking enough care in the application, which doesn't sound like the case. 10 doors is still not that much though. I've edge banded all of the shelving in my cabinetry as well as 3 euro jobs. Not once have I had a failure of edge banding coming off.

One could make some really nice looking shop cabinets using mdf doors, not even edge banding them. Just round the corners well. I wouldn't do that for a customer though. It would get some hardwood edges.

 

[DC INC]

I've had poor success with ply doors, even using 3/4" Baltic birch (15 plys) I'm about ready to say f#ck it and switch to particle core or mdf, which I always thought was inferior chit, but it stays flat

 

[blackte]

I will agree with the heat trapping part. The edge banding...something is wrong there. Either you are getting bad edge banding or you aren't taking enough care in the application, which doesn't sound like the case. 10 doors is still not that much though. I've edge banded all of the shelving in my cabinetry as well as 3 euro jobs. Not once have I had a failure of edge banding coming off.

One could make some really nice looking shop cabinets using mdf doors, not even edge banding them. Just round the corners well. I wouldn't do that for a customer though. It would get some hardwood edges.

I think you are correct on the edgebanding part. It seems that in places the tape does not stick and then needs re-heated to make it stick. I think I just need to play around more with it to get the correct amount of heat and pressure to make it work properly.

Thanks for the advice.

 

[CarpenterSFO]

Get fans in there - properly mounted to exhaust hot air from the top of the cabinets. It may take the doors a little time to un-bow; it's not the heat so much as the humidity gradient through the door.

Iron-on edge banding works fine, if you're careful.

I agree with other comments that your door construction was unorthodox. Hopefully the fan will fix the problem and you won't need to build new doors.

 

[BBuild]

There should be two outlets on the back of the receiver for a powered sub. I would plug a computer fan into the extra outlet. It will turn on with the receiver.

 

[Morning Wood]

I agree with the solid wood being a problem. Since they are painted, putting solid wood edges on a piece of mdf core birch ply would be more than satisfactory for what your are doing.

 

[Gus Dering]

As like most small shops I don't have access to a good edgebander. I do have a hot air bander, but I would not trust it with something like this. I have looked around to rent, nothing. If I had a way, I would have went that route, would have save me time, money, headaches and the such. Still looking for a used one.

There is a used Brandt for under $12000 in here

http://www.sismachinery.com/equipment/index.htm?utm_source=SIS+-+Everybody+List&utm_campaign=86c706a6dc-2012+-+08+New+Arrivals&utm_medium=email&utm_term=0_b3d96d1670-86c706a6dc-44925533

 

[Spencer]

One of the first big lessons I learned when I started doing cabinetry was exactly what you just did. Glued up the same size poplar doors with an routered edge detail to match some existing cabinets. Going out perfectly flat and beautiful. Two weeks later they were unrecognizable. Bowed and twisted beyond comprehension. I don't think they'll be coming back...chalk one more up to school of hard knocks.

In a world of perfect conditions it would be fine. But as you're finding out the lightest climate difference will make them go wild.

Out of curiosity what was the width on your strips that you glued up?

 

[PrestigeR&D]

Poplar frame I can see,...but doors are not a good candidate for using that species.....to much exp/cont.......your talking 1-1/2" rips to make a solid panel out of a species that likes to move.....

Go glue some strips.....narrow ,pile them together....clamp.dry,....set it on your bench.....watch what happens to that after 1 year of climate change......



Hardwoods ,....rips are ussually around 3-1/2" - 6" repeated - depending on the set up, and species.....


JMPOV ,....

MDF for doors......
Not a big fan for using that material for doors......,week mechanical bonding,dents and impressions are not to difficult to put into MDF....JMPOV on that,.....

Moldings,.....that's different...

I prefer ply- 11 ply 3/4" Birch; band it and you will be in good shape for some longevity,,,,.



JMPOV,.....



B,

 

[blackte]

There should be two outlets on the back of the receiver for a powered sub. I would plug a computer fan into the extra outlet. It will turn on with the receiver.

This is Audio/Video Equipment, that never shuts off. They leave it running 24/7. This morning I arrived to install adjustable shelving and the temp inside the center cabinet was 86 degrees.

There is a used Brandt for under $12000 in here

I wish I had that kind of money to spend.

One of the first big lessons I learned when I started doing cabinetry was exactly what you just did. Glued up the same size poplar doors with an routered edge detail to match some existing cabinets. Going out perfectly flat and beautiful. Two weeks later they were unrecognizable. Bowed and twisted beyond comprehension. I don't think they'll be coming back...chalk one more up to school of hard knocks.

In a world of perfect conditions it would be fine. But as you're finding out the lightest climate difference will make them go wild.

Out of curiosity what was the width on your strips that you glued up?

The crazy thing about this entire project, is there are 7 more doors that are done the exact same way, and they are prefectly fine.

All of my materials are stored in house for at least a month, and then ripped, planed, glued, sanded. On these I used 1 1/2" wide by 13/16 thick.

I understand that this probably was not the best option for making the doors, but I also understand that many people have had issues with using plywood for doors. So, I guess this will be a lesson learned, but I'm not sure that anything could stand up to almost 90 degrees of constant heat and not deform. I will take the advice and move forward. I'm guessing that I will be building at least 3 new doors, in the short term future.