Replies

1. 
   k1c | Nov 05, 2010 01:12pm | #1

   foam crown

   I saw the joints being glued with latex or polyurethane caulk/adhesive, but I think heavy caulk will leave smear mark that can not be sanded.

   One idea may be to hot glue a spline on the back to maintain a tight joint.

   Another idea may be to install kind of dedicated clips close to eachother at the joint.

   Did anybody try something like this?  Thanks in advance.

1. 
   Piffin | Nov 05, 2010 07:14pm | #2

   U mite try BT Classic

1. 
   k1c | Nov 08, 2010 08:49am | #3

   foam molding

   Thank you for reply. I will look into it.

2. 
   Mark | Nov 15, 2010 09:06pm | #4

   I just installed some of this stuff a couple of days ago.   I did the "hot glue with a spline behind the joint"  method.   That part worked ok,   but there really just isn't any way to make the joint look great due to the fact that you can't sand this stuff at all.  

   add that to the fact that the H.O. bought all 8' sticks and there were a LOT of those "not so good" joints.

3. 
   calvin | Nov 15, 2010 09:40pm | #5

   A long time ago.........

   I had a job where they purchased that old style foam moulding-more like plastic smooth on the outside, an open stiff foam on the inside.

   I didn't think any scarf joint would work and it was a ceiling cove, not very big-so but it was.  I inserted pins of clipped 6 finish to help keep the registration on the face.  I don't think I glued them-was worried about dissolving the substance.............

1. 
   k1c | Nov 15, 2010 11:26pm | #6

   foam molding

   Thank you Mark and Calvin for the replies.  I have warned the HO about the joints in this molding and the fact that they don't come in longer lengths.  Because of the lower material and labor costs, they want to try it, at least in the smaller diningroom.  Then we'll see if they want to use it in the livingroom with longer length walls.

   Someone in the diy website recommended wetting the joints and using gorilla glue, but I would be worried about the joint getting pushed out of alignment by the glue.

   This is my plan:  to have the joints land on one clip and use urethane caulk to reinforce the joint.  There will be no squeeze out.  Whatever needs filling I plan to use white wood filler that comes out of a tube. 

   Again, thank you for the replies.

1. 
   calvin | Nov 15, 2010 11:35pm | #7

   One other thing

   Might try one of the "crazy glues" like 2P10 from fastcap.  Quick set and a darn tenacious glue.  I've used it b/4 on corian, pvc, wood and some other substraits-can't break the joint (when fresh-as it gets older in the bottle it loses set time and strength.

   Glued a customers sone plastic goal posts on one of his games.  He was one happy boy.

   You could cut the lengths, join till set and then install all in one.

4. 
   k1c | Nov 21, 2010 06:42pm | #8

   foam crown molding

   Just put it up and it looks good, except that joints are every 8 feet, but joints are tight.  I'm including this post in case somebody searches for the topic and ends up thinking joint on one clip is good idea - it may not  be.

   I had to use plain foam molding that just gets glued and nailed.  This molding did not have the grooves in the back for the clips.  I thought I was to use another kind of molding but the HO chose no clip molding.

   I used polyurethane adhesive and a nailer.  At first I thought the nailer (paslode finisher) would damage or dent the foam but it was baseless worry.  I used butt joint.  Joints did not meet perfectly because (I suppose naturally) no 2 pieces are same.  I first matched the bottom joint then either pull the top out a little (shim) or hammer the top in a little for the face to match up.  I couldn't adjust like this if I used clip system and put the joint on one clip.  In fact, I would put the clips at least 16" or more away from the joint so that joint ends can be manipulated a little. 

   I nailed it into the sheetrock, just to hold the molding until the caulk sets up, about every 20 inches.  I used dap caulk for the joints. 

   Having done this, I now have some doubts about the clip system.  Using the clips, the molding may not line up or install tightly to the surfaces.  You would have to do more caulking at the seams before the painting.

1. 
   calvin | Nov 21, 2010 07:00pm | #9

   Thanks for the explanation

   I appreciate your experiences with this stuff.  Pity they broke the picture posting ability-would have been nice to ask you to show it.