Tinted finish chipped on bass body - repair options?

[Mottlefeeder]

The body wood has a nice grain and is heading towards mahogany colour, but the original finish has a tint to give the final walnut colour finish.

The original finish is around 1mm thick, so I don't think I can just use an oil as a finish. That pointed me towards 'seal, tint and layer up to fill the crater', and thinking that a water-resistant PVA would do the trick.

I'm now looking at superglue. I'll start by checking whether it bleaches out the existing tint, and if not then I'll layer it up to fill the crater. I'm trying to minimise the amount of sanding due to the risk of creating more damage to the surrounding area.

David

[Mottlefeeder]

Sorry if I seem to be tiptoeing round nail varnish - it is solvent based, and I'm worried about what it might do to the original finish.

David

[Maude]

The lemon oil I linked to wasn't meant to be a suggestion for finishing, but an addition/reaction to the copper tape post above it. Sorry if it confused.

 

From the the thickness of the original finish I'd say it's polyester,  or possibly polyurethane. 

They're both chemically cured by adding a catalyst. The two parts mix and react by cross linking the molecules to form a polymer which is basically an impermeable plastic. It cannot be dissolved by adding a solvent in the way that a nitrocellulose finish can be, so nail varnish won't have any detrimental effect at all. 

 

Just to add, if you're using a waterbased product to stain/colour the wood then you're better using a solvent product to build up the clear layer as it won't mix with/redissolve the waterbased colour and make it bleed or blotch. 

 

If you've got your colour sorted, good old Poundland superglue (3 bottles for a quid) is very good as an easy to use clear filler as well. 

 

[Mottlefeeder]

I checked the bass this morning and found part of my PVA had peeled away from the original finish. I pulled at the loose end and the whole lot came off, so I am almost back where I started, except that I now know more.

The original tint appears to have gone into the wood, so by next job is to find out whether superglue will change or move the colour, or whether I can just start building up layers of clear.

David

[Ralf1e]

On 08/08/2022 at 17:31, Mottlefeeder said:

I parked the car on a slope, opened the boot and failed to catch the bass as it slid out. It landed on the thinnest bit of padding in the gig bag.

 

The finish chipped down to bare wood, with one crater on the edge of the top/side, and the other on the edge of the top/side/base, The left hand crater is about 15mm long at the bottom. The craters have sloping edges, making the finish look deeper than it is (about 1mm).

I made some enquiries and one luthier declined the job, and one quoted £175. Going to Allparts for Gluboost would cost £50-£70 for a range of colour additives and some glue, so I thought I'd look for some alternatives locally. 

 

Hobbycraft have a transparent PVA glue and some water based transparent colours so I thought I'd have a go, mixing the colours on a transparent film so that I could see them against the wood.

 

I painted the damaged are with PVA to seal it, and left it to dry. Then I mixed some mid brown with some red and got a surprisingly good match. I mixed that with some glue and painted it on. This is how it looked when it dried.

 

This is the crater with about 6 coats of PVA over the tinted coat. I'm getting there, but it is a slow process, partly limited by the risk of the glue dripping if I put it on too thickly.

 

And finally, my question - If I changed horses in mid stream, would Gluboost complete the job faster, or would it also drip off the edge?

 

David

 

I have had some limited success with super epoxy quick setting. It sets very hard and can be rubbed down and buffed out with finishing compounds.

[Mottlefeeder]

2 hours ago, Ralf1e said:

I have had some limited success with super epoxy quick setting. It sets very hard and can be rubbed down and buffed out with finishing compounds.

Thanks for that, but at the moment I'm going with superglue. Did your epoxy set transparently or with a bloom?

David

[Ralf1e]

On 01/09/2022 at 13:58, Mottlefeeder said:

Thanks for that, but at the moment I'm going with superglue. Did your epoxy set transparently or with a bloom?

David

The one I used sets clear after the bubbles come out but looks clouded as mixed. I think different makes of epoxy can come out a bit coloured.

My difficulty was colouring the bare timber under the chip concerned before building up with epoxy. I used a brush and did several layers sanding between each then final sand and polish using mixed types of buffing wheels on a drill. I will try to take some photos later. I wasn't going for perfection TBH. It is on a B stock Spector Euro LX I was never going to do an invisible repair on that finish. I also used super glue in the repair to touch up tiny cracks on the damage. I have no idea how Andertons ended up with that damage on a £2500 bass but as I got it for £1540 and its not in an obvious place so I can live with that. I am sure yours will be better disguised by the time you have finished.

[Mottlefeeder]

Time for an update.

I managed to buy the  thicker superglue from a site with a 2 week delivery, so nothing happened for a while.

I checked that the glue did not bleach the existing wood dye, and then put on the first coat. When it dried I noticed that there were now flecks of white in the original finish around the new glue, which was worrying, but they came off by wiping with a damp paper towel.

To be safe, I shrouded the working area with masking tape, then put on a few more coats. Unfortunately, trying to get viscous glue to stay put on an external corner is much like telling a cat to do something. The result was the the glue spread as far as the masking tape, and also created bulges that I am now in the process of filing down.

In summary, superglue is going to work, but it is going to be a long job.

David