How to restore finishes and plastic parts?

[SweetMelisma]

I searched and didn't find anything so here goes...

I like fixing up cheap basses from craigslist or garage sales or where ever for myself and for my students. In fact, they usually end up playing better than they probably did from the factory. I can make them play well and sound good, but I'm not too hot at making them look good. I can shine up metal parts and take care of the fingerboard, but when it comes to finishes (usually poly on these guys), I'm a complete rookie. Honestly, the people who end up playing these basses usually aren't advanced enough to tell that they feel good, so looks are important for overall satisfaction in this niche.

It would be a great help to me and I'm sure others if somebody experienced in this (or in car finish work) could chime in with their approach, with steps if possible.

To be clear, I'm not talking about stripping a finish and putting a new one on or starting from scratch, I'm talking about taking a used bass with the normal swirly pattern of minor scratches all over the body, pickguard, and electronics cavity cover, and the occasional deeper scratch, and making it look new again (or at least close).

Since a number of tools and/or products will be needed, I'll let you know what I have that I think might be pertinent. I feel that my collection isn't too "advanced" and therefor would be a good starting point reference for other people wanting to do this too. Here goes:

- "normal people" sand paper (60, 120, 220, 320 grits)
- finer sandpapers (400, 600, 1000, 1200 grits - all wet or dry)
- Stew-mac cloth-backed finishing papers assortment (400, 600, 1200, 4000, 6000, and 8000 grits)
- Dremel 4000 with the basic buffing wheel bits that came with it
- Naptha and some other chemicals
- Fender Mist and Wipe, Trick brand Drum Polish
- Dr. Duck's Ax Wax
- Dean Markley microfiber cloth
- Rags and blue shop towels
- Brown paper bags
- Various old Turtle Waxes and stuff I found in the garage

Any help would be appreciated! Thanks.

[SweetMelisma]

Here's a picture of what I'm talking about. It's the ol' classic Squier Affinity P-Bass.

[202dy]

Given the above example, it is not cost effective to perform the service. Here's is how to do it and why it should not be done.

The best way:

1. Remove hardware and electronics.
2. Remove neck.
3. Rub out with 600 grit.
4. Buff on stationary machine.
5. Reassemble.
6. Setup.

If one is a speed demon and not too particular about the final product, that service can be performed in approximately an hour and a half.

Stationary buffer? Absolutely. Hand buffers leave a different kind of swirl pattern. The finished product will be shiny but it won't look right. Unless it is a vintage Martin, in which case it will look perfect.

Down and dirty:

1. Remove strings, pickguard and neck.
2. Rub out with 600 grit.
3. Continue rub out with micro mesh to 12,000 grit.
4. Final buff with Meguiars #7 or similar.
5. Reassemble and set up.

If one is a speed demon and not too particular about the final product, that service can be performed in approximately an hour and a half. The difference is that one will be tired afterward.

So how much is your time worth? Assuming a cheap shop rate of twenty five dollars and hour the service costs a minimum of $37.50USD. That is if everything goes according to plan, the planets are in alignment, the phone doesn't ring, and the baby doesn't cry. Two hours costs fifty bucks.

Most shops charge a minimum of $50.00 an hour. Less than that and they will be out of business in short order.

In the final analysis, the cost of the cosmetic service is between $37.50 and $100.00. This is exclusive of setup or any other work. The guitar will retail for $125.00 on a good day. Add the cost of acquisition and some strings puts this transaction solidly in the loss column.

Leave it alone.

[john grey]

I can't add that much to the above: that pretty much whats happening but when you're buffing you would want to experiment w/ two issues.
If the body has an acrylic top coat; it's going to look pretty good with a lower speed buff with wax as the wax will fill the scratches fairly well so you return to a gloss. Keep the speed lower to moderate or you'll heat the acrylic and ruin your effort! Obviously you need a real automotive wax of a high gloss & heavy weight in this instance.

If the body does not have a clear top coat then you have to proceed with caution. Start with hand-level polishing. In ancient times the paints were very often genuine automotive materials. But don't assume anything. If you don't think there is a clear top coat then use a furniture polish and hand buffing with a rough towel. Let it set and dry; do it again. Furniture waxes will be some of the lightest ( a bee's wax and surfactant). If your scratches are too deep it's generally better to smooth them down with a polish & wax then try to touch them up. Overall you will not get a good touch-up unless you are using a micro air brush/compressor & have a stone righteous color match.

[SweetMelisma]

Thanks for the replies so far.

I'm not too worried about putting in more time than the instrument is worth. That's sort of my whole intention. A fret level alone would almost cost the same as the value of the instrument, but it greatly improves the overall playability of the instrument. I'm not looking to sell for a profit, I'm looking to get my students playing with instruments they can afford that will give them the best chance to develop good technique and not hold them back. It's in my best interest to put in some unpaid time to supe up their axes. For example, I've been working with one of my students on using harmonics, but he can't use his bridge J pick-up because it hums too bad in that room. Sometime in the next couple days I will be shielding and star-grounding that thing so that hopefully he can finally use his bridge pick-up and get nice sounding harmonics.

I'm not averse to buying a few new tools if it's necessary and not too expensive. Is a stationary buffer pretty much a must-have for this sort of stuff?

Are the micro-mesh considerably different than the finishing papers I have? Enough different that I would need to buy them?

Thanks

[john grey]

A great deal of this depend on how you prep and what the individual problems ARE. If you're going after a full body cleanup then the neck's going to come off and you'll hold the body. You COULD put a hand buffer in a vise or clamp or clamp the body - but the concept is to control to movement of the buffer so you don't end up with "digs" and bumps.A hand buffer is tough to control unless (let's say the body is totally stationary). One of them has to be kept from moving.

However sometimes a hand buffing with a semi rough cloth like a towel can deal with certain scratches, such as the fingernail marks in a body with no pick-guard and a lot of "learning to slap" scratches under the G string. This also depends on the final finish (if it's a clear acrylic). There is a trick with a polymer auto wax and a towel that can get some fairly obvious scratches if you have a clear coat on the paint.

I have a rule that I follow: I always do the least, first. If that works I move on. Too often a minor scratch becomes a demand for a total re-paint because of hitting it too hard: to quickly. Use a light touch first and see if you get results you're satisfied with. This is a mandatory element with acoustic instruments. But it's advise that saves a lot of cussing at the wall.

Remember that once you ARE sanding: you are then going to refinish - there's no turning back. Try to make the existing finish work for you first. Micro mesh will remove more than wet/dry becasue of the mesh design. If you ARE thinking of re-paint, then learn about colors, and using a micro air brush and compressor. That's the only way to fly. If you're even doing a few inches, you match needs to be excellent and the rest of the body has to be stripped and roughened or you'll have a vivid "cleaned-up spot".
Automotive paint shops have color matching software and a scanner. They will frequently give way a sample of a half pint; which will cover a body if you have a good touch and have mid-to high end air brush equipment. Refinishing Necks can be challenging because you have to have a finish that doesn't "grip" in to a sweaty hand. Nitro works IF you let it really dry. It's generally 25% nitrocellulose and 75% acetone. You can use ping-pong balls but they don't have as high quality a nitro as the real thing. You want it to dry clear and hard. That's the finish that will "yellow" very well with age. But if it doesn't dry appropriately it will be gummy. It needs a VERY dry place to set up. A humid environment will screw up a nitro finish.

If you want to avoid this use an oil finish: it looks great and has a lot of flexibility. The only real rule is that you KNOW what your body looks like (some are two piece and won't look too good unless you get creative). Porous woods will DRINK oil so you need to know when to use a sealant or seal type oil like tung - linseed can seal also if applied and left till dry then buffed by hand.

[rojo412]

Mother's Billet Polish and Maguires Plastic Polish with a rag of your choice can go a LONG WAY to helping some of the forgotten basses of CL get way cleaner looking.

Only once did I pull apart a 93 Fender J Plus and wet sanded with 1200 grit, then hand polished it with the Billet polish and it came out AMAZING!!! But it took forever.

My only word of caution is to avoid trying to clean up gold hardware with those. They clean off the GOLD!