plastic weld

I am assuming the you intend to use a hot air welder, if so then you might be able to join them, but the weld would not stand up to much stress.

When dissimilar plastics are melted together, they tend to laminate, rather than fuse. Olefins (PP or PE) can generally be welded to each other, but polymers of different chemical make up generally will not fuse.

PVC is most successfully "welded" with solvents, olefins (PP or PE) can be welded with a heat source and a filler material.

I do know of coextruders the can join PVC and olefins, but they generally use an intermediate EVA or compatiblizers (we call them (foo foo dust" or "snake oil")to allow dissimilar materials to bond.

If you care to share some of the particulars of your project, we might be able to come up with a work around. Or you might ask the same question over at Sci.polymer. Those guys have forgotten more about polymer chemistry than I will even know. They have been very helpful in the past.

Greg

good day, GREG: object in question is an older plastic (undestructible) PVC windsurf board. the molded/recessed area near the footstraps collapsed and fractured. was planning on removing the section, and replacing with a slightly thicker piece (with a routed "lip" creating ~1" margin) so as to make the surface flush with rest of deck. have hot air welder, but as you suggest, chemical may be the way to go (both??) thnx,

dogalone wrote: :

Wi th a little web crawling, you should be able to find a bit of PVC sheeting and chemically bond it to the wind surfer. You might try Mc Master Carr of Cadillac plastics for the sheet goods..... Since the wind surfer is older, it probably is suffering from a bit of UV degradation, so be sure you lightly abraid (sand) the surface before you attempt any chemical bonding. (THE UV "rusts"the PVC, well actually oxidizes the PVC, but since this is a metals based group, thought rusting plastic sounded better ).

Good luck greg

good evening, GREG: with the help of the group am hoping luck will not be a factor. the patch is set to be cut out an 1" larger than the cutout in the board, the idea being to put the 1" shelf on/around the top side of the replacement piece. abrading the existing undersided surface (which may not??be UV degraded); going with the adhesive method(s) described and sealing the butted section with the welder.. there is nothing in the title (of this group) that in any way limits the discussion to metal (which as i hazily/vaguely recall, are defined by how packed the orbitals are) thnx (again),

dogalone wrote: snip

What is the thickness of the material you need to insert as a patch...

What color?

greg

Try this

part # 8747K112

thickness of board material (to be repaired)is nominal/metric around

1/8" and is still white; selected patch material is hoped to be white and about 3/16" (allows for routing the ~1/8" "shelf"). weight (specifically lack of it) is an issue here...

thanx for your interest!!

do you figure the grey stuff to be any stronger than the white? or perhaps more/most easily welded/joined??

thnx

I have found Tap Plastics to be good supplier of various plastics for projects.

Here is a link where PVC sheets of different colors can be obtained:

Good luck, Rich

wow! great site; thanks (luck doesn't even seem to be a factor on this one!!)