|Forum topic by Lifesaver2000||posted 11-27-2009 01:39 AM||2712 views||0 times favorited||4 replies|
11-27-2009 01:39 AM
About 9 years ago, I installed built in shelving into an addition to my house. The shelves were made of 1×10 pine that the local building supplier sold as “shelf boards.” While not exactly furniture grade stuff, they were flat, straight and smooth, requiring only a little round-over on the edges and light sanding before painting to match the wall they were attached to. I don’t remember the exact price, but I do remember it seemed pretty cheap for what they were. The final product turned out very nice.
I am planning to start a remodel of a bedroom this winter. One wall will have a fold up bed, with built-in looking floor-to-ceiling shelves on each side, similar to those in the addition. One problem I have found though, is that the building supplier no longer sells these “shelf boards.” What they want to sell as an alternative is a 1×12 board that is no where near the quality of the other boards. They are neither flat, straight nor smooth, and the price is quite high, at least to me, about $20 for an 8’ board. I live in a rural area, and don’t have a lot of choices. The Home Depot 25 miles away doesn’t really have an equivalent to those “shelf boards” that I have found, so I have been looking at using 3/4 inch MDF. Since the shelves will all be painted anyway, I’m not concerned about anything like grain or things of that nature, and I can get what amounts to 5 1×10 boards from one of their $23 49”x97” sheets.
The questions I have are:
1) How does the strength of MDF compare to pine lumber the same size? The shelves I built 9 years ago are supported at about 2ft intervals, and have been able to handle full loads of heavy books without even a hint of bowing or movement. How will MDF handle this type of load, and will it bend over time? Would I need to support it at closer intervals?
2) I live in an area where the humidity varies quite a bit throughout the year. It can be as low as 25 to 30 percent in the winter, and up to 60 percent in the summer inside the house (my A/C is set up to keep the humidity level down even if the temp is cooler than the thermostat setting, so it never gets over 60 to 65 percent.) Will this much of a change cause problems with the MDF?
3) Any other problems I should be aware of? I’ve read about the dust production when cutting/routing, and also about how this stuff wears out blades/bits faster than the pine would. I have read conflicting reports concerning getting a good paint job on it though. Some say it takes paint great, others say not so much, and most say that getting the edge to look good is the hardest part. I have read a few tricks for sealing the edges, such as glue mixes or sheet rock mud. Anyone here have any experience with this?
I realize this isn’t exactly the kind of “fine woodworking” that is usually discussed here, but I have seen from reading through the forum that there is plenty of knowledge available, so I am hoping to tap into that knowledge base so I can save some time/money/frustration. Thanks in advance for any help you can give.