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fiber tear out - any remedy?
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Author:  ayavner [ Sat Sep 05, 2009 10:06 pm ]
Post subject:  fiber tear out - any remedy?
.... no metamucil jokes either!

So here's the deal, was just scraping the binding on the top and snagged some glue that came up and pulled a nice little wad of fibers up with it. Not sure if it will sand out or not, seems to be rather deep, so I don't want to take a chance at trying to sand it and dish out the area.

If it was for sale, of course I imagine it would be a deal breaker, but as its not, does anyone know of a way to mitigate this somewhat? will the finish fill the area somewhat?

Frustrating, because i was so careful when pulling up the binding tape not to pull up the fibers, and now it looks like my dog took a scratch at it.

well... probably not that bad, but harshed my mellow for the day.

thanks,

adam
Author:  ayavner [ Sun Sep 06, 2009 1:07 pm ]
Post subject:  Re: fiber tear out - any remedy?
Hi Filippo -

You are correct - the spruce top, towards the bottom of the lower bout near to the purfling. The wood was bare. Any ideas?

thanks!
adam
Author:  the Padma [ Sun Sep 06, 2009 1:46 pm ]
Post subject:  Re: fiber tear out - any remedy?
Yo, the Adam

Ok the glue to use is CA...go to Stew Mac...its staine only on the surface and will disappear when sanded out.

If the tear out because of "soft or punkie grain...flood it with the thin CA...let cure, scrape away and sand away.

If the tear out is splinters...then reset with CA...let cure scrape and sand away.

If material is now missing...well your call as to
A)
try and match with a patch of similar grain...working with the grain lines....CA as above.

B) mix fine sawdust from the top with CA and patch...and is probably the most noticeable repair.

Remember...soft rowie, punkie grain loves to be stabilized with CA.

Finally its your call as to just sanding it out or practicing you inlay work.

blessings
the
Padma
Author:  David Newton [ Sun Sep 06, 2009 2:14 pm ]
Post subject:  Re: fiber tear out - any remedy?
Adam,
What Filipo was referring to was the practice of sealing, or flooding the top, (actually the whole guitar) with clear shellac as soon as the body is whole. It does a lot of things, fights soiling as you are working is one, but the main reason is to resist tear out at routing the channels, and at scraping the binding / purfling. It hardens things up and helps, although tearing and chipping can still occur even though sealed, so attention to the direction of router travel is still important.

Now, what to do with this one? I would still seal the entire thing now. Filling with CA would be next, as the Padma says. Don't try to sand the CA full of spruce dust, if you have any dark wood in the purfling, it is guaranteed to fill with the dark wood. After hardening, the fill may minimize when sanding the top, but it still may show. Who cares? I don't. Your next one will be perfect.
Author:  ayavner [ Sun Sep 06, 2009 3:54 pm ]
Post subject:  Re: fiber tear out - any remedy?
Haha, thanks guys! Well.. David... doubt my next one (or 100) will be perfect, but I definitely won't be writing in for this issue again :)

so, as it appears, the Padma nailed it first off - the wood in that area just appears punky, so the fibers just kinda lifted right up and out. Now don't get me wrong, its not like it is visible unless you know to look for it, but it sticks out like a sore thumb to me.

So in this case, you recommend a sealer coat of shellac, followed by flooding the area with CA before final sanding? Will the shellac limit what I can use for a final finish? I woudl think not, but safer to ask. How about a locally applied clear shellac burn-in stick?

thanks for all teh responses!

adam
Author:  the Padma [ Sun Sep 06, 2009 5:19 pm ]
Post subject:  Re: fiber tear out - any remedy?
Yo, dude

If it is "punky" wood....use the CA first..to soake into the grain and harden it..sand then shellac.

If you shellac first...the penetration will not be very deep and the CA will only sit on top of the shellac and you will still have punky wood under a paper thin layer of hardness.

So now that you know what punky wood is...you will know what to watch out for right after the first surfacing of the wood...looks punkie or other flaws...send it back.

Shellac is pretty well the sealer of choice for all sprayed finishes. Oil finishes will float on it and not go into the wood. DO NOT buy liquid shellac as its shelf life is about 6 months, you know when is gone off cuz it will just not dry...ooie gooie gummy ...always mix it up fresh...brush / but spray is best. google shellac and read.

Blessings
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