Advice on fixing edge chips in top and back

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Woodsy23
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Advice on fixing edge chips in top and back

Post by Woodsy23 » Sat Apr 01, 2017 11:48 am

Like Rocket, I decided to "broaden my horizons" by building a couple of mandolins. During some over exuberant planing of the plastic binding with a violin plane, I gouged some chips in the European spruce top and red maple back. I would appreciate advice on the best method to repair or conceal them. I plan to do a classic sunburst finish using nitro so the edges of the body will be dark. I think filler would show up through the finish and am worried that glue lines will also show up if I try to glue in slivers of wood. My inclination is to leave them and drop fill with nitro during the finishing process.

Any opinions?
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Richard

simso
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Re: Advice on fixing edge chips in top and back

Post by simso » Sat Apr 01, 2017 11:54 am

Have you considered doing a burst edge in your paintwork.

If it's going to be clear final finish, then nothing you do will hide it, if you are going to add a slight stain to the whole instrument, then you can graft a couple of small piece in, the stain in the lacquer will disguise it fairly well

Steve
Steve
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Do your own repairs - http://www.mirwa.com.au/How_to_Series.html

Craig Bumgarner
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Re: Advice on fixing edge chips in top and back

Post by Craig Bumgarner » Mon Apr 03, 2017 10:32 pm

Beautiful mandolin. A burst is a good idea, certainly in character for this one. If you are committed to a clear finish, you can at least try to blend pieces into the chips. Hopefully you have some of the same wood left (I save my cutoffs until the instrument is done and gone for just this kind of thing).

Work clean, sanding dust and grimy fingers are not helpful. When you are sure things are clean and dust free, wipe the surrounding areas with super blonde dewaxed shellac (made from flake) to prevent glue absorption. Or, apply some egg white with an artist's brush. Regardless, keep it out of the repair chip itself. Cut and fit the wood bits. Try to match the grain and figure as best as humanly possible. Be patient. Work with good light and over a soft surface that will catch the bits when you drop them. (you will drop them!) Be patient. Glue with hot hide glue or fish glue Do not use CA or aliphatic resin glue as these will likely darken the wood. Once the glue is fully cured, sand it out. Do not sand before fully cured or the tacky glue will trap dark particles and make the glue line show.

On the spruce chip, you might consider extending the chip to the next dark grain line, to the right in your picture, that will help hide the lengthwise joints at least.

On the maple, I might consider filling with a clear filler. I'd experiment on scrape first. Nitrocellulose lacquer might seal the color first, then fill with clear CA. Again, try on scrape first, it might darken up on on you. Not all CA cures crystal clear.

Hopefully this works. If not, consult wabi sabi philosophy, accepting imperfection can be liberating. If you can't stand it, go for the sunburst.
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Craig Bumgarner
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Re: Advice on fixing edge chips in top and back

Post by Craig Bumgarner » Mon Apr 03, 2017 11:19 pm

... then fill with clear CA.

Or, drop fill with nitro, multiple times. Nitro is very clear.
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rocket
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Re: Advice on fixing edge chips in top and back

Post by rocket » Tue Apr 04, 2017 7:53 pm

Noice very Noice :cl :cl

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Mark McLean
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Re: Advice on fixing edge chips in top and back

Post by Mark McLean » Wed Apr 05, 2017 10:52 am

Yes, don't let a couple of minor imperfections blind you to the fact that you have made a very beautiful mandolin.

Craig - that tip of taking a graft insert up to the dark grain line is a really nifty one. Will definitely write that down somewhere.

Woodsy23
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Re: Advice on fixing edge chips in top and back

Post by Woodsy23 » Tue Apr 11, 2017 12:52 pm

Thanks everyone for your tips and advice.
Richard

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