Mini Vacuum Table

[jonson]

I can picture the jig that you describe. Is heat a problem? What RPM?

I run a pillar drill at about 1000 rpm for that John and no heat problems although first few I did like that did melt back together but I found I wasn't going quick enough and was allowing the blade to heat up so now it's a quick pass on all 4 sides and then nip the corners. It's the cleanest way I've found though I know Spence does his on a belt linisher and gets superb results. Dare I say it with all this Gibson single in a bucker crap going on but his covers he does for them are superb. Spence started off with a Dental vac and did well but I made him one like yours and also mine and he doesn't use the dental one any more.

[John_H]

I run a pillar drill at about 1000 rpm for that John and no heat problems although first few I did like that did melt back together but I found I wasn't going quick enough and was allowing the blade to heat up so now it's a quick pass on all 4 sides and then nip the corners. It's the cleanest way I've found though I know Spence does his on a belt linisher and gets superb results. Dare I say it with all this Gibson single in a bucker crap going on but his covers he does for them are superb. Spence started off with a Dental vac and did well but I made him one like yours and also mine and he doesn't use the dental one any more.

Cool, thanks for the info. I've got one of those little saw blades. I'll give it a try. So far, I've been doing the final trim with a belt sander, and then a sanding block. It's tricky to get them level. I do need a different approach for more consistent results.

I've always admired Spence's work. His stuff is top shelf. I miss seeing his posts here.

[jason lollar]

I tried one of those dental vacuum formers- I wouldnt bother, its of limited size- barely big enough to make a strat cover, they dont get very hot and the hand pump type vacuum takes too long to ramp up and is pretty weak. Your better off getting an old mattel vacuum toy from the 60's that has been reconditioned to hook up to a pump or shop vac- they get WAY hotter than the dental models. The things they use to let kids play with! I had one and bought a rebuilt one off ebay about a year ago

[John_H]

I didn't think those dental former's looked like they would work too well. The most consistent results I've gotten have been by heating the plastic in the oven. My shop vac is pretty powerful, and pulls it right down.
I've been too busy to mess with it since the other day, but some time this week I'll do a set of custom covers for a bass I'm making.

..The things they use to let kids play with!...

Yep, toy's were better back then. I bet my minibike was safer though than the lawnmower I had to use.

[jason lollar]

how about yard darts?
I used my shop vac- it works great.

[David Schwab]

Your better off getting an old mattel vacuum toy from the 60's that has been reconditioned to hook up to a pump or shop vac- they get WAY hotter than the dental models. The things they use to let kids play with! I had one and bought a rebuilt one off ebay about a year ago

Yeah! I had that Mattel Creepy Crawler thing where you molded rubber worms and insects in a very hot metal mold! And you know what? I didn't burn myself. Not once. The thing said "Warning HOT!" and I paid heed! Teach kids to change jointer blades... lol That will make them respect danger!

Being almost 60, here's what I notice; These days people worry needlessly about kids. We can say that things were different back then, but they weren't. People are just paranoid these days. I had a man try to get me to go with him in his car back in the 60s, so that shit is nothing new. Now people don't want their 12 years olds to walk up the street alone. And as far as toys, I think it's more that the manufacturers are worried about lawsuits.

[David Schwab]

In my day I had this! Think of all the ear drums you could rupture with this contraption! lol But we didn't.

[John_H]

I need a white dogear cover, so I bought some white High Impact Poly Styrene. It's very easy to work with compared to the ABS that I've been using. I'll have to get some of this in black. It draws down very smooth, and clean.

[jonson]

Nice to see you go to hips plastic john it is that much easier and the colour range far exceeds that of abs.

[John_H]

I knew I'd probably end up favoring the styrene from what I learned with my original experiments. I didn't think working with the ABS was very difficult until I got some HIPS sheets, and did a direct comparison. When I was first researching this, and looking for suppliers I found this company > Thermoform Plastic Sheets for Vacuum Forming - Styrene, ABS, PETG, Polycarbonate - Vacuum Form Your Own Prototypes, Packaging, Molds, and Scale Model Parts I went with the 9 X 9 format because one of their common sizes was 18 X 18. The nine inch squares are quite adequate. I tried some at 6 X 6. They were too small for decent results with the ABS, however they might be ok for the styrene.

I spent a few hours yesterday making forms for a few different styles of covers. The first new design I'll be experimenting with will be variations of a Fender XII. I've never made a jig for flatwork that small. (should be interesting) It was cool to be able to make a dogear cover the right height for a T-O-M. Thanks for all of the help on this.

[John_H]

Up close. A couple from the batch last night. The black one is .10" taller.

[Jason Rodgers]

This is cool! So many possibilities!

Stupid question: can you wax pot a whole pickup and cover assembly without the thermoform plastic going squishy?

[John_H]

This is cool! So many possibilities!

Stupid question: can you wax pot a whole pickup and cover assembly without the thermoform plastic going squishy?

There's no problem potting. The plastic doesn't get soft until about 350* f.

[Jason Rodgers]

There's no problem potting. The plastic doesn't get soft until about 350* f.

Great!

A couple more questions. I've watched some of the first hits videos on youtube about vacuum forming, so I'm guessing you're doing this, but I thought I'd ask...

- Can you show some of your positive forms? Your first post, 2nd photo shows what I'm guessing is the single coil oval MDF chunk in the lower right hand corner. How are you making these (aside from "very carefully" )?

- I saw one guy on youtube suggesting baby butt powder for form release agent. Your photos have some white dust on the table: is this what you're using?

- Following that question, are you slightly tapering the sides of your forms to facilitate release, or just straight sides and a good yank?

- Do you leave the cover base "skirts" a little tall to allow for height adjustment (that can be sanded down to height with sandpaper on the top if it's an archtop, for example)?

Thanks!

[John_H]

- Can you show some of your positive forms? Your first post, 2nd photo shows what I'm guessing is the single coil oval MDF chunk in the lower right hand corner. How are you making these (aside from "very carefully" )?

They aren't high-tech at all.

- I saw one guy on youtube suggesting baby butt powder for form release agent. Your photos have some white dust on the table: is this what you're using?

Nope

- Following that question, are you slightly tapering the sides of your forms to facilitate release, or just straight sides and a good yank?

I do put a slight taper to them. Otherwise it's very difficult to get them apart.

- Do you leave the cover base "skirts" a little tall to allow for height adjustment (that can be sanded down to height with sandpaper on the top if it's an archtop, for example)?

Thanks!

I make them taller than needed so that I can have a clean edge once they're trimmed. When you form them, they tend to roll away, and get thin at the very bottom.

Most of my experience with this is right here in this thread. I looked at a couple of videos, and had at it. I'm by no means an expert. Give it a try.