Back painting acrylic pickguards? also shaping acrylic?

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dylanafghjkl
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Back painting acrylic pickguards? also shaping acrylic?

Post by dylanafghjkl » Thu Apr 19, 2018 5:54 am

I have some thin acrylic coming in the mail to make pickguards and I'm wondering if anyone has any ideas on back painting them a la rickenbacker, gretsch, a bunch of custom builders.

I'm thinking that I should cut them out first then paint the back with rattle can gold (i might do a test piece with some craft acrylic paint to see if you can see texture through it + to see if it'd stick)

I'm also wondering if there's any easy diy way to get a bevel on the edges? if I don't have to make routing templates it'd be better but it is possible for me to get some made

also does anyone have any experience polishing acrylic with a heat gun? I've been looking at flame polishing but I'm worried that with really thin acrylic it'd bubble before it polished but I don't have much experience with working with acrylic outside of using it for templates.

Thanks in advance

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rhubka
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Re: Back painting acrylic pickguards? also shaping acrylic?

Post by rhubka » Thu Apr 19, 2018 7:51 am

I'm not a pro at this but have tried a few things.

When I back paint acrylic I sand the surface to 400 grit first. The paint sticks better, runs less and is more scratch resistant and it looks the same as not sanding.

I use a small hand held plumbing propane torch when I flame polish acrylic edges but am usually doing about 1/4" thick edges. I never stop moving the flame. You need to practice on scraps first! I have caught the acrylic on fire a few times!

My pickguard edges are all done with a router using a 45 degree V bit on templates or... (Sorry :whistle: ) on my CNC machine. I have seen video's of some using a dremel tool with a small sanding drum and those who use several files.

Just my 2 cents worth. Hope it helps.

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Re: Back painting acrylic pickguards? also shaping acrylic?

Post by hpr_hpr » Thu Apr 19, 2018 8:04 am

- Best (fastest will least chance of screwups) . . . template with router
- A dremel with a sanding drum will work BUT you need a stand so you can use two hand to position the piece on a flat surface or you almost guaranteed to get an uneven edge ... one slip and . . .
- Progressively finer files will work fine . . . and can be relaxing if you're that kind of person . . . . and has minimal chance of issues as you are moving so slowley . . . getting nice even curves is a bit of a challenge though.

Rough cut with a jigsaw with a metal blade (fix it firmly to a scrap piece of wood or acrylic the thickness of a pick guard may crack) or hacksaw first in all cases.

Flame polishing a edge on 1/8 acrylic is a bit dicy as there is very little material to disperse the heat. I would think practice first is a MUST there even if it's only to prove that it will (or won't) work . . . better (safer) may be to use progressively finer sandpaper to around 1500 and then use polishing compound with a polishing wheel on a dremel or by hand . . . it's only a very small area so it's going to be hard to see the difference between absolutely completely polished and a very fine satin . . .
When thinking about any advice given always ask yourself "why would (s)he know more than I do".

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Re: Back painting acrylic pickguards? also shaping acrylic?

Post by Con-Tiki! » Thu Apr 19, 2018 10:06 am

The post above agrees with what I was going to suggest.
I've beveled with files, but straight edges look nice , especially on thinner material.
Wet-sand and polish the edges. It only takes a few minutes, and less dangerous than a torch
(Christopher, also)
I've been to one World's Fair, a picnic, and a rodeo, and that's the stupidest thing i ever heard come out a pair of headphones.

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dylanafghjkl
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Re: Back painting acrylic pickguards? also shaping acrylic?

Post by dylanafghjkl » Thu Apr 19, 2018 8:23 pm

update: i ordered the acrylic a week and a half ago and e-mailed the place yesterday asking for a tracking number and got an e-mail back saying something along the lines of "uhhhhhhhhhh yea we....sent that" and got a notification from aus post that they'd express posted it soon after and it arrived today!
Image

Thanks for the replies everyone!
I'm thinking my best bet will be double sided taping the acrylic to some masonite then shaping it all the way attached to the masonite so I have a template to route the bevel (i have a roundover bit but it's going to be way too big so I think I'm going to go for a 45°)

I'll do a test piece of flame polished with heat gun but I'm guessing I'm probably going to go for wet sanding and buffing wheel because the acrylic I got was 1.5mm (1/16") and I think it's just going to burn it straight away.

Thanks for the tip rhubka about sanding the back to 400 first! I was thinking about it from researching painting directly over poly for refins but I'll definitely do that!

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hpr_hpr
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Re: Back painting acrylic pickguards? also shaping acrylic?

Post by hpr_hpr » Fri Apr 20, 2018 11:06 am

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I'll do a test piece of flame polished with heat gun but I'm guessing I'm probably going to go for wet sanding and buffing wheel because the acrylic I got was 1.5mm (1/16") and I think it's just going to burn it straight away.
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You are probably correct, the winner the smaller the margin for error there . . . . . not sure, does a heat gun get hot enough to do the job?

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(i have a roundover bit but it's going to be way too big so I think I'm going to go for a 45°)
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Incomplete rounders can be nice ... do a test piece with different parts of the rounder and see if you like it . . . . note that at some settings you will cut into the template.

Not sure exactly what kind of double sided tape you are using to but another method is to use two pieces of painters tape (one on the template and one on the work piece) and glue them with superglue . . . The double sided stuff I get here is much ticker and kinda squishy which makes for a less than perfect medium for bonding stuff to templates . . .
When thinking about any advice given always ask yourself "why would (s)he know more than I do".

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