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Glue joints noticeable under finish?
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Author:  Rvsgtr [ Fri Jul 04, 2008 12:25 pm ]
Post subject:  Glue joints noticeable under finish?
I've just realized that on a couple of guitars I built there are some glue lines receding (for lack of a better term) and there is a tiny line in the finish in and around some of the bindings, endgraft, top seam, back seam, etc. I think it will buff back out (after some laborious and tedious wetsanding) but i've figured out it all came from the same bottle of LMI white I purchased a few months back. My last guitar had ivoroid binding where I used CA and its fine around the CA but noticeable at the top seam and backstrip areas. All the binding is slick as glass. The joints are fine but there is a hairline flaw there no doubt about it. I'm a little put out about it to say the least. Anyone else had this happen.

I know for sure I'm going to HHG for top and back seams or back to titebond which I had used up until about a year or two ago and never had this happen. Any help or ideas would be greatly appreciated.
Author:  Mike Collins [ Fri Jul 04, 2008 2:03 pm ]
Post subject:  Re: Glue joints noticeable under finish?
What did you use for a sealer of finish on this guitar?
mike
Author:  Rvsgtr [ Fri Jul 04, 2008 2:44 pm ]
Post subject:  Re: Glue joints noticeable under finish?
McFadden's for the first time. The other guitar had spirit varnish sealer on the top and Behlens vinyl sealer on back and sides. What do you think?

thanks.
Author:  Mike Collins [ Fri Jul 04, 2008 3:09 pm ]
Post subject:  Re: Glue joints noticeable under finish?
With sealer I treat it just like the final finish.
I put it on a bit heavy-allow to completly shrink(dry)
Varnish takes more time to completely dry!
Then sand just a bit with 320.
If i go through i apply more sealer -let dry then start the final finish.
If you allow your top coats (add an extra coat)to dry throughly and then level you'll be fine!
Try some sample pieces with all the different finishes you've tried and fine the one that caused the problem.

Mike
Author:  Rvsgtr [ Fri Jul 04, 2008 4:48 pm ]
Post subject:  Re: Glue joints noticeable under finish?
thanks for the help. I'll try that. It just seemed it was the glue. I may not have gone thick enough with the sealer. I know lacquer tends to "run away" from various compounds and I may have gotten my sealer too thin. Hopefully you're right and all will be well with the world. [:Y:]

In lutherie just when you think you have everything figured out you...well... [headinwall] ...you get the picture(pardon the pun).
Author:  John Hale [ Fri Jul 04, 2008 5:12 pm ]
Post subject:  Re: Glue joints noticeable under finish?
At the moment I'm hating superglues (CA) I'm starting my first and my rosette left something to be desired so I filled the gaps with wood dust and superglue and it's wicked up the spruce end grain and left amber marks in places I nearly sanded through the rosette trying to get rid of it at the moment I feel like buying a new top, but won't this is a first so there'll be more mistakes on the way and it's a learning process!
Author:  Rvsgtr [ Fri Jul 04, 2008 7:39 pm ]
Post subject:  Re: Glue joints noticeable under finish?
Always seal your rosettes with lacquer or vinyl sealer or even shellac before using CA. It wicks real bad and you can't fix it. Otherwise, if you seal the cavities CA works great for rosettes. The same goes for spruce tops and bindings. Just seal the edge of the spruce and you'll be fine. I usually seal and wait a day or two before proceeding on.

Best of luck. And by the way, I've ruined a few really nice tops so don't fret. It's just wood as my luthier buddy always reminds me. Just be glad it wasn't a $1000 set of brazilian or something.
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