Let’s see- a few things;
Foam ain’t that great a material to stick things to. Lots of little holes, not a lot of actual surface, and dust will happily get into all the nooks and crannies and you got tape stuck to dust. Dust is your enemy. Vac it with a brush that’s stiff enough to get it loose and you’re getting it as good as ya reasonably can.
While the 3M blue sticks to stuff like a glossed board really well, the glue isn’t so great for porous surfaces like foam. The tradeoff is that the 3M glue doesnt dry out as quick so ya can leave it there for a while and the junk-brand tape has a pretty aggressive glue that’ll stick better but it dries out and gets to be a permanent problem. One word of warning: some of the cheap tapes have a glue /adhesive that leaves a residue when something containing styrenes is used with it and soaks in some. It’s soluble in acetone, that residue, but it’s a pain to have to deal with.
Could be the soft foam has bigger ‘pores’ so ya got less to stick to, but I don’t think that matters a whole lot.
As for curves: while guys like pro-pinstripers use some real narrow tape and stick it down flat, something to remember is you don’t necessarily have to. If your good side is reasonably flat and the other is wrinkly and folded over itself, so what? As long as the edge you’re going to be cutting to is on the right curve and not horribly lumpy, let it go, you just want something to cut to and keep the cloth from sticking to what’s under the tape. What I’ll usually do is run the tape along, pushing one edge down to the line, the other side is wherever it is, then lightly come along and push down the tape so it isn’t flapping, but as to whether it’s perfectly flat I could care less. Kinda like this:
I’ve got one nice flat edge that’s on the curve, great - so any glass that’s to that edge will lay flat on what’s under it, foam or previous lamination, and when I cut to that edge it’ll be fine. If the rest of the tape is up a little, folded and so on , it doesn’t matter, I’m gonna cut it loose and chuck it anyhow.
I tend to go along, tape roll in one hand and my other hand guiding and pressing down just one side of the tape and pushing it down right to the line - I don’t worry about sticking all of it down across the width. The rest of the tape is up away from the surface, perhaps, like you’d do tape along the rails for a hotcoat or gloss. I can always come along later and crudely push it down if I feel like it. It’s a Good Idea, by the way, if your cloth is not too oversized for the laps, so it ends up about midway on the tape someplace. You can get away with some very wide tape, used this way - as I found out when I had some midnight repairs to do and all I had on hand was 2" masking tape.
hope that’s of use
doc…
