Make your own covers.

[Spence]

Thanks, and it is something I've thought about. My main concern is the surface finish. Since the form is under the plastic, I'm assuming any details like logos and stuff wont show well.

My big pain at the moment is the logos... I can get covers cheap enough, and they are easy to work with, but it cost me 3 times the cost of the cover to have my logo laser etched on them!

I'm going to try and make some molds, and just cast the whole pickup/cover in one shot.

You could get some lettering laser cut in stainless steel and fix them to the top of the former if you want raised lettering. Believe me, even wood grain shows up in the palstic!

[David Schwab]

Believe me, even wood grain shows up in the palstic!

Oh really? Could be just the ticket then.

[Bruce Johnson]

I'm no expert on vacuum forming, but I believe that you can also pull the plastic into a female mold. That way, the outer surface of the cover would be directly against the mold. You'd have to have holes placed carefully in the mold to draw the air out through, such as magnet holes.

For putting a nice logo on existing plastic covers, another technique is heat stamping. The tool is similar to woodburning, a copper block with your logo machined into it, heated by an electric element. To heat stamp plastic, you heat it to a much lower temperature, just enough to soften and deform the plastic. With a rig like that set up in a small arbor press, you could make nice logos in seconds. With some plastics, you may be able to imprint the logo with pressure alone, no heat.

[jonson]

Well Bruce spotted it Spence and yes correct that is another way to do it. It will then, by doing the mold in reverse, pick up all the woodgrain and any logo that has been designed into the mold. But, on narrow pickup covers a pressed plug as in a stamp would be required to push down as well and that type of mold is not as easily within the scope of the home vacuum fraternity.

[Spence]

Well Bruce spotted it Spence and yes correct that is another way to do it. It will then, by doing the mold in reverse, pick up all the woodgrain and any logo that has been designed into the mold. But, on narrow pickup covers a pressed plug as in a stamp would be required to push down as well and that type of mold is not as easily within the scope of the home vacuum fraternity.

Perhaps I should have mentioned that I tried both before using the method I have now. If I have to make an extra effort to make something rather than buy something ready made, it's got to be relatively easy, time efficient and cost effective.

[Bruce Johnson]

and that type of mold is not as easily within the scope of the home vacuum fraternity.

Why not? It doesn't have to be complicated. Carve up a wooden plug that fits inside the female mold, minus the thickness of the plastic. Attach a handle to it. As the soft plastic is drawing down in, manually push the plug down in to seat the plastic fully into the female mold. Let it cool, then pop it out.

Get your minds out of the gutters, guys....

[jonson]

I was talking about machining a female mold Bruce not the plug. Plugs and male molds are easy to do, and females well within your and my scope but somebody without the equiptment we have will be a bit pushed, and be back into spending money again.

[lion]

Spence - could you give some details re the type of plastic material you are using, thickness ect.

[Spence]

The type of plastic you use must be vacuum formable. You can use plastics like styrene and abs and HIPS. I use 1/2 mm and 2mm thicknesses.

[lion]

OK - thanks. Styrene, ABS and HIPS (high impact polystyrene, right?).
I'm wondering about the finish seen in your pictures, do the covers actually turn out like that after the vacuum forming?
Would you mind giving some details re your vacuum setup?

[Spence]

The covers are always longer than the finished article but the sheet plastic has a shiny side so it looks just like you see in the pictures.
That is except for the styrene I use. That has to be polished with a buffer.



This stage shows the flat finish. At this stage I add artificial injection mould marks......





,,,,,and typical cracks that you can see on 50's styrene covers and then polish them.


I use a commercial vacuum forming machine which is designed for the job.

So Lion, who are you?

[lion]

Thank's for the replies and pics - much appreciated.

Well -who am I. A newbie to the Pickup Makers forum, but proably a "little dated" on most other things . Picked up the guitar in the early 60th, enjoyed music/playing ever since. Living in DK and having a good time tinkering with guitar rebuild/restoration, DIY amps, electronics ect. Found this forum (your thread) by a google search for a specific reason.

I'm in the process of restoring a nice Burns Nu-Sonic dated 27. april '65.
Making good progress, but I'm still missing a few parts, including 2 pickup covers. The Nu-Sonic differed from most other Burns guitars (with Tri-Sonic (type) pickups) by having injection molded plastic covers, and also in size they are nothing like most pickups covers (see pic).

Replacement pickups to original specs are avaiable, but not the covers. My only option seems to be to make reproductions. So I've set out to research the mysteries of vacuum forming, and any help will be appreciated.

[jonson]

Hello Lion and welcome. Bit Strange for Jim to go to the bother of having a mold made for those pickups as most of the Burns runs were small. The First Bison basses were only made in a batch of 48 and most other early Burns were small runs as well. If it was an injection mold then that may well have been done by Eddy Cross in his smallish workshop in Ilford UK. Eddy, "sad to say no longer with us", was a real nice guy and did all the scratchplates and the engraving on them, they wern't stamped out but machined. Maybe that cover was injection molded or vacuumed and then engraved I don't know which without seeing one again. If you are going the vacuum route you will not get the lettering and line work in there as crisp as they are but go the route I go and engrave them afterwards. You need a guy with an old style engraver, belt run and capable of reduction so that a large ply copy of the pickup top can be cut and then the machine will reduce that down. I do that with vintage knobs by making a copy knob, engraving it correctly and then make a new mold in rubber with all in place. Keep Spence talking and you will learn a lot.

[lion]

Strange indeed, with the Nu-sonic pickups. I can't say for sure wheater the covers were injection or vacuum molded - but I'm told it was the former and also that they were quite cheaply made, and tend to become brittle and split.

I'm aware that the letters and lines has to be engraved afterwards - but as the engraving seems to be more or less worn of on most originals anyway maybe I'll simply omit that part - I'll make that decision when I get there.

Instead of making new covers as per the original I could simply use standard Tri-sonic pickups, and make some kind of pickup rings to cover the larger cutouts in the Nu-Sonic scratchplate (kind of like the Red Special), but I don't think that would look right.

I've found some general info on DIY vacuum forming, and it seems not that complicated - but it's probably not that simple in real life, and I'll have to look further into it.

[Spence]

Thank's for the replies and pics - much appreciated.

Well -who am I. A newbie to the Pickup Makers forum, but proably a "little dated" on most other things . Picked up the guitar in the early 60th, enjoyed music/playing ever since. Living in DK and having a good time tinkering with guitar rebuild/restoration, DIY amps, electronics ect. Found this forum (your thread) by a google search for a specific reason.

I'm in the process of restoring a nice Burns Nu-Sonic dated 27. april '65.
Making good progress, but I'm still missing a few parts, including 2 pickup covers. The Nu-Sonic differed from most other Burns guitars (with Tri-Sonic (type) pickups) by having injection molded plastic covers, and also in size they are nothing like most pickups covers (see pic).

Replacement pickups to original specs are avaiable, but not the covers. My only option seems to be to make reproductions. So I've set out to research the mysteries of vacuum forming, and any help will be appreciated.

I haven't seen any of these for years. Are they engraved, hot foil stamped or just screen printed? The latter would wear off with time and Jonson's a dab hand with the screen printing.