PVC trim board welding itself back together

[jskd82]

I am using a scroll saw to cut my pieces out but the pvc welds itself back together.... I'm guessing it's melting from the blade friction.  Is anyone having this issue and is there a fix?  Or maybe the scroll saw blade is too thin and not creating a big enough gap after the cut to keep it separated?

[mark poulson]

Be sure your blade is sharp, and makes a wide enough kerf.  Try adding a thin wedge to the cut behind the blade to keep it open.

[jskd82]

Thanks! I'll give those tips a try.

[Travis]

What blade are you using?  I would think something like a no 9 skip tooth would work well.  

Something like an Olsen FR45000.    I say Olsen just because easy to get at most big box stores.       

 

 

[Big Epp]

I have had this problem too, even with hand saws.  It's been pretty interesting trying to work the blade out once it gets welded in.

[mark poulson]

19 minutes ago, Big Epp said:

I have had this problem too, even with hand saws.  It's been pretty interesting trying to work the blade out once it gets welded in.

What brand of PVC board are you using?

I used to use AZEK decking, and had some machining problems, but since I switched to their trim board the problems have gone away.  Maybe the decking has more of the actual PVC material, since it's stronger and heavier, and that's what's sticking/melting.

 

[Travis]

I have never had issues with the stuff welding together on my bandsaw or table saw.   Any of my handsaws cut through it with about as much difficulty as balsa.

I did get it to melt on the lathe with just riding the bevel and have melted it with a dremel (30000 RPM).  However I hate using the stuff so avoid using it as much as possible. 

 

 

[Big Epp]

36 minutes ago, mark poulson said:

What brand of PVC board are you using?

I used to use AZEK decking, and had some machining problems, but since I switched to their trim board the problems have gone away.  Maybe the decking has more of the actual PVC material, since it's stronger and heavier, and that's what's sticking/melting.

 

I am using the deck material.  I don't remember what brand, but I ripped the deck boards down and then cut off the surface with a bandsaw.  Come to think of it, I didn't have any trouble with the table saw or bandsaw, but the narrow blade of the scroll saw and the narrow blade of my coping saw both get stuck.  I have also melted it on a lathe, which is really frustrating!

[mark poulson]

When I use the belt sander on PVC deck boards is when I get melting, if I try to take too much off at once with a fine belt.  I don't seem to have that problem with 60 grit.

I sometimes get wispy trailers, like spider webs, if I try to rip it on the table saw with a duller blade.

Heat buildup seems to be the common denominator, so keeping my tools sharp, whether it's hand tools or power tools, has been key for me when I'm working with PVC, especially the deck boards.