The Upholstery Forum

Hi, I've sewn some 50mm pleats into vinyl with a 6mm foam backing. Here in Australia the foam is called Cerex. Its like a scrim foam that has a backing that will hold a sewn thread.
I now have air pockets in the vinyl. ( see picture). They weren't that obvious at first but have developed over a couple of weeks.
I didn't use any glue, because as far as I can tell, the glue is only to stop everything moving around while you're sewing.
Any idea what's causing the air pockets? Should I have glued the lot first?

Bob

6mm foam is typically not thick enough for the vinyl to "pull" down into the seam resulting in the baggy appearance you've got. Bump up to 10mm foam and you'll find your current approach should work fine.
The only time I've got away with 6mm foam was using fabric instead of vinyl.
Someone with more experience than me may have a method that does work for 6mm foam and vinyl.

James is right, thinner foam can be a bit more finicky. Usually steaming the panel and installing it on your project will resolve this completely. How ever you should still be able to avoid this all together.
I would strongly suggest using a light spray of cheep spray can glue ( AKA: Temp Tack) to hold the fabric to the foam while sewing. In my opinion its important because even if you do not shift the fabric on accident the machine may slight feed the to different materials a small bit off.
Using glue on pleats is a big controversy in the upholstery world with 1/2 swearing by no glue and 1/2 swearing to use glue. Glue has always worked best for me and what I was taught by my teacher.

If that doesn't fix it then some other possibilities could be thread tension too tight or the the presser feet pressure is to high or too loose.

@JamesLey @John

Thankyou James and John,
I'll get some glue and have a look at tension/pressure etc.
I'm doing a door panel, and thought that 10mm or 12mm foam would be too thick. Do you use the thicker foam on door panels?

Wouldn't they go away when you stretch it out over the piece to be covered?

I've done door panels with both 6mm and 10mm. I prefer 10mm if I'm doing pleats as they look more plump, but use 6mm for plain door panels.
Trim the foam level with the edge of the door panel and thickness is no longer an issue really.

@JamesLey
When using the 6mm on a plain design with no pleats, do you contact glue the vinyl to the foam with 100% coverage and then also contact glue the foam to the door panel

I feel like part of that is the stretch direction of the vinyl as well. I tend to glue them together, but if you have the stretch going with the seams vs perpendicular to the seams, it tends to want to bunch up like that. The narrow panel has less to give than the longer pleated section does so the material naturally settles in the direction of stretch. That's just my experience anyway.

bajintas wrote: ↑Fri Oct 01, 2021 10:29 am @JamesLey
When using the 6mm on a plain design with no pleats, do you contact glue the vinyl to the foam with 100% coverage and then also contact glue the foam to the door panel

I do glue the vinyl to the foam, and foam to the door panel yes. It's only a light coating though, it doesn't need a huge amount.