I’m finishing out my basement using pre-primed fiberboard (MDF?) base trim 4 1/4″ tall (from HD) and need to trim around about a 4ft curved section of wall. It’s an outside curve & not a super small radius, but probably enough to snap the piece if I just force-bend it. Just guessing, I’d say its maybe a 4 or 5ft radius and like I said probably 4ft long
Anyway, I’m hesitating ordering a small piece of flex molding from a couple on-line places that I saw mentioned in another post… I thought maybe it’d be easier to just do some kerfs on the back side and give it a try (problem is its late & I’m too tired to do it right now!).
Any simple solutions you folks know of? You think the kerfs might do the trick? It’s not wood trim, so I’ll bet steaming it would just make it fall apart.
thanks!
Broice
Replies
Depends on how thick the base is 3/8ths? 5/8ths? On How easy it is to bend. For some tight ones I find it helps to coil up the base overnight. With 3/8" base you can easily take a 14' length and wrap it in a circle. 5/8" base might want to snap, so bend it as far as you can and block it on the floor overnight. That way the base has a chance to stretch oth the outside and compress on the inside. MDF will bend pretty tight if you give it a chance to adapt.
Cutting kerfs has never worked for me on MDF, the curve never looks smooth, you can see every cut, if it doesn't snap.
For really tight curves I cut the profile off the top of the base and install a build up of the bottom flat profile with 1/4" MDF. After I build up the lower section I can usually get the upper profile to bend and then caulk the joint to hide any gaps.
MDF is cheap, you could certainly afford to break one piece. I don't think you'll have a problem unless it is over 3/4" thick. Steal your wife's sewing measure tape for taking the length. Start fastening at the top of the curve and work your way to the ends. It may help to do it incrementally over a couple days instead of forcing it all at once. You may want to use trim head screws for the pulling power. If it doesn't work you can look at alternatives. Kerfing the back with shallow, close together kerfs so they won't telegraph through. Layering with thin strips or using flexible molding.
Like the others have stated MDF tends to sag and bend on its own . You could set it on a couple of saw horses and let it sag for a day or two . Would make a great weekend prodject . set it up on fri with some weight and come back on mon and install.
Why not do that one section with pine? If you want something that's really flexible use that plastic stuff. I wrapped that around an 11" radius once. I had to use roofing nails to hold it down. LOL
Thanks for the tips! I'll probably to bend the trim a little at a time, maybe over a couple days or so.... If that doesnt work I'll try some of the other suggestions
thanks again!
-broice
I have never kerfed mdf, use wood instead. Kerfs have to be the same depth and the same distance between kerfs to work correctly. I have kerf bent stair risers to a 9" radius this way. I kerf shorter pieces like 4'-0" on a table saw with a jig similar to a box joint jig, only larger. Your radius is easy to kerf as it is a large one.
mike
I agree Mike... only thing is, I dont know if HD has the same profile in pine. I'll be checking though, if the bending of the MDF piece doesnt work.
thanks
-broice