Hello Everyone. I am making some exterior window sills from PVC. This has involved gluing up 3/4″ thick “boards” to create thicker stock from which to mill the sills. I have two questions that I would appreciate your thoughts on.
First, what is a good way to conceal the glue line between the two 3/4″ pieces of PVC? Will paint adequately fill this seam? Or do you need to apply something like Bondo or some other filler to the edge?
My second question is related. When milling the beveled sill surface, the texture left by the saw blade is pretty grainy. What do you guys recommend to fill that surface or to smooth it out? Just sanding it? Or fill it with something and then sand that?
Thanks in advance. I appreciate any thoughts.
Replies
Make your cuts oversize and use an electric plane to get to the size you need. You may need some sanding even after that.
The glue line joint will be similar to a wood glue line joint. Paint should cover it but you could smooth it with a paintable caulk or Ready Patch. You can sand down the rough sill pieces but a little roughness will help hold the paint. I've made my own sill nosing pieces from PVC and have had good luck doing this.
Most manufacturers recommend sanding with 300 grit paper but I would suggest taking it slow or it will melt the pvc. They also suggest the use of acetone to seal the cut edges. I didn't find the acetone worked very well unless I gave it a dozen passes. Also the cut edge is a dirt catcher so I would make sure you paint it to give it more slickness. I thought I could get away not having to paint the trim but that wasn't the case.
HI there, Just another option... buy the pre-made PVC sills... there are at least 4 different profiles available, and you can modify those easily too to get what you want...