Replies

1. 
   Greg_Warren | Feb 10, 2001 06:19pm | #1

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   s,
   I see it all of the time in custom. But cut the jambs and casings in after any finished flooring. We flooring installers and tile setters like to cut the bottom of the jambs to slide our flooring under them. The problem is that if there are any tight spots, and there will be, if one has to readjust a flooring cut to fit better, the mdf tends to break off when one pulls the piece out. It makes something that looks nice in the beginning look ugly. Installing it after flooring installations is the way to go. GW

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   Phill_Giles | Feb 10, 2001 07:54pm | #2

   *Nothing better for paint grade (get the paper-coated kind, not just the primed) - it looks good, goes up easily, takes less toll on the environment, is economical, takes paint well, is stabile, is reasonably flexible, and does have all the bad habits, like warping and checking, that cheap wood has.

1. 
   Rick_A. | Feb 10, 2001 08:00pm | #3

   *s,I just finished my own house last summer and I used a lot of MDF for the finish work.All of the base, 6" tall with a base cap profile, the crown molding, chair rail, corner cabinet, and the walk-in shelves and drawers.The base and crown came pre-primed. The rest I cut from 3/4" x 4' x 8' sheets (HD about $15 a.)The negatives:It's difficult to trim or shape with a utility knifeIt's very difficult to cope to a point. But after a couple of times with a saw I tried a small rotozip tool. It worked great, and was faster too.Sometimes, when shooting it, the mdf puffs out around a countersunk nail head by the force of the gun. A couple of light taps with a hammer pushes it back down flat.Don't bother to shoot outside miters, most of the nails do a 180 when they hit the 45 of the other piece. You're better off drilling and hand nailing (and glueing of course).Handling long lengths is a pain because it's heavier and bends alot more than wood.Then there is the question of VOC off-gasing. But since it is painted and sealed I don't consider it an issue.The positives:The cost is considerably less that similar wood mill work.It's very hard, It takes a lot of force to make an indentation.Even the carpet installers didn't damage it. There were rub marks on the paint from their tools but the mdf itself wasn't damaged.It cuts very easily. The routered edges were very smooth.The surface of the mdf is extremely smooth, it gives you a nice finish after it's painted.The thinner stock (base) bends easily so it can be used for radius work.It comes in 4' x 8' sheets so I was able to cut an entire frame for an 8' corner cabinet out of one piece, no joints or seams.At this point we are near the end of the heating season and looking around I don't see any evidence of movement other than small openings between the base and the walls but that is probably due to the frame movement. All of the outside and inside corners are perfect. On the other hand some of my wood molding has some shrinkage.So far I like the stuff.Rick

1. 
   s_meacham | Feb 12, 2001 06:08pm | #4

   *Any idea what the minimum radius is for bending the base?

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   Ron_Teti | Feb 12, 2001 09:07pm | #5

   *Guys good stuff but i need to state the obvious. please keep it out of bathrooms or anywhere it could come into contact with water.

2. 
   Rick_A. | Feb 14, 2001 04:50pm | #6

   *I was able to bend a 12' piece of base to a 7' diameter semi circle without and curfing or wetting.I also installed it in my bathrooms as a test case. I made sure to seal all of the edges with finish semigloss. So far nothing has swelled or moved. Even the part that butts up to the fiberglass shower unit quite often has water drops on it (we have shower curtins) but still shows no sign of movement. Rick

3. 
   MIchael_Brown | Feb 17, 2001 02:46am | #7

   *I have used MDF alot lately. You have tokeep water and moisture far away from it. It is, after all only saw dust and resin. Another thing others havent mentioned: it doest hold nail very well from the side. It would be better to screw into the side. I agree though..it paints great!

4. 
   Mongo_ | Feb 17, 2001 03:25am | #8

   *It's somewhat delicate when knocked on it's corner...I'd advise against using it on high-traffic door casings if you think there's the likelyhood of repeated dings. If the corner gets whacked it tends fracture in a layered fashion and pieces can crumble or break off. Especially so if you want to add a decorative bead to the traffic-side (inside) edge of the casing. I'd also avoid using it for window stools. Water concerns, etc.It's a nice product when used wisely. I often combine it with poplar in paint grade trim work.

2. 
   s_meacham | Feb 17, 2001 03:25am | #9

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   Would like to use 3/4" MDF for base and casing. The base will be 8" high total. What are the positives and negatives with using this material in place of wood?