Repairing chips in a poly finish

[Jono Bolton]

My P Bass previously had a bridge cover fitted, which requires one small screw hole either side of the bridge. Now, whoever drilled these holes can't have been too handy with a drill, because they've caused the finish to split and chip away, leaving two circular chips about 5mm across. They're both down to the wood, although the wood isn't dented, it's as though the poly has just been lifted off the body.

Is there anyway to fix this without resorting to a full refinish? The rest of the finish has a bit a of wear (the body's 15 years old) but it's mainly just scuffs and surface scratches, whereas these 2 chips are pretty unsightly. I don't want to go down the route of any ghetto solutions like black marker or nail varnish, I'd rather do it properly but I can't help thinking that it would be difficult to get that thickness of finish in such a small area. Could a luthier sort it?

[HowieBass]

Video here of a guy using super glue to fill the chip/hole first before using paint/lacquer over the repair (video only shows the first stage)

http://youtu.be/Xr2kUhVekxU

[Andyjr1515]

I agree - I would use thin cyano (superglue) for this kind of thing. As the guy on the video says, you have to be quite careful and it does dry VERY hard so not overfilling too much is important because, while trying to scrape or sand off the excess, it is easy to add another gouge in the untreated poly.

[Bloodaxe]

Dan Erlewine's take on CA drop-filling:—

[media]http://www.youtube.com/watch?v=rTVScFJoe24[/media]

The bit on strip sanding is pure gold dust, as is his tip about honing the razor blade.

[Kiwi]

Jon Shuker uses strip sanding for tricky parts too. The tip about turning the razor blade into a scraper is pretty neat though. I've used nail polishing pads in the past instead of specialist wet n dry. They seem to work really well.

[Jono Bolton]

Thanks for the replies fellas. I'd seen the Dan Erlewine video after watching the one posted by HowieBass as Youtube had linked them together, it's very informative, I really like his videos. He does it differently though to the first video, where the dent is filled first and then sprayed over afterwards, Dan drops in a bit of colour first and then glues over the top before sanding. If I did it that way, what would I fill it with in terms of colour? Would I have to get a can of black laquer just for two chips? Bear in mind that the wood is currently exposed where the chips are, if there was any colour left I could have just filled it with glue and then blended it in.

[Bloodaxe]

Black nail varnish?

[Jono Bolton]

[quote name='Bloodaxe' timestamp='1411980809' post='2564435']
Black nail varnish?
[/quote]

That did cross my mind, or maybe acrylic paint/model paint.

[Pete1967]

You could colour it with a bit of black marker pen and then drop fill it with CA, or buy a small bottle of black CA which is available from some luthier supplies. Be careful with strip sanding. You can easily sand a hole. I'd stick with a small block.

[Jono Bolton]

[quote name='Pete1967' timestamp='1411988769' post='2564506']
You could colour it with a bit of black marker pen and then drop fill it with CA, or buy a small bottle of black CA which is available from some luthier supplies. Be careful with strip sanding. You can easily sand a hole. I'd stick with a small block.
[/quote]

Would this glue be suitable?

[url="http://www.shop4glue.com/black-colour-thick-cyanoacrylate-adhesive-super-glue-superglue-stays-dark-black-when-set-gap-filling-543-p.asp"]http://www.shop4glue.com/black-colour-thick-cyanoacrylate-adhesive-super-glue-superglue-stays-dark-black-when-set-gap-filling-543-p.asp[/url]

[Pete1967]

I've only ever used the low viscosity glue so I can't comment. Black CA is black because it has black rubber in it so sometimes it doesn't dry rock hard. I've had success by flowing some black off the end of a scalpel blade in to the bottom of the ding and then building the rest up with normal clear stuff. Do thin layers and build the black up until the wood is covered.. The first coats will sink in. Patience is your friend...

[Jono Bolton]

[quote name='Pete1967' timestamp='1412101690' post='2565711']
I've only ever used the low viscosity glue so I can't comment. Black CA is black because it has black rubber in it so sometimes it doesn't dry rock hard. I've had success by flowing some black off the end of a scalpel blade in to the bottom of the ding and then building the rest up with normal clear stuff. Do thin layers and build the black up until the wood is covered.. The first coats will sink in. Patience is your friend...
[/quote]

Cheers Pete, I've ordered a small pot of black acrylic paint and I'll use that to fill the bottom of the chips, then build up clear glue over the top. First job is to fill the screwholes while I wait for the paint to arrive. Looks like I'll have a wee project on the go this weekend!

Edited October 2, 2014 by Jono Bolton

[Jono Bolton]

This is proving to be a bit trickier than I anticipated. Because of the screw hole that has now been plugged, the acrylic isn't sitting flat in the bottom of the chip. I've tried building up a couple of layers to get it level but there's stiil a couple of peaks and I'm getting very close to the surface, giving me very little room to fill with glue. I'm worried if I fill it with glue now, it'll be too thin and I'll run the risk of sanding back through into the acrylic after scraping with the blade.

My plan now is to use acetone to clean the acrylic out of the chip, and remove the plug in the screw hole and start again, only this time filling the screw hole with glue until it's level with the wood, and then putting a layer of glue over the top of the chip to seal it. Once dried, I'd put a couple of layers of black, and then glue over that once it's dried, creating a sort of glue-acrylic-glue sandwich. Before I go ahead and do it, does anyone know if that would actually work, or am I going to balls things up even more?