:hny4
Thanks Allen.
Anyhow I have lots of stuff that I'm meant to be doing with family right now but I have put my foot down, I showed them all who the man of the house is and said "I don't feel too well schnookums, I had better not come along cause I'll only spoil everyone fun, you go scwheety pie, you'll have a much better time without silly old me hanging around to worry about. I'll just stay home in bed and rest up so I can get my strength back and maybe do some stuff around the house one day soon" Anyhow, once I got rid of them, I slithered out to the shed.
The truth is though that things are still too wet here in WA to glue the top on so I decided to work on the fretboard for that guitar I showed the bracing pattern on a couple of month back
Yeah, yeah, my slackness aside lets move on. I have this sort of theme that has developed on this guitar. I have been using Mulga and bookmatching the yellow gold sap wood to form a central blaze. I already laid up and fitted a thin decorative wedge shaped back strip and a butt wedge that have both been laid up with this blaze. I used Titebong original to bond up the bookmatched veneers for these inlays. Titebong worked OK, but given that the sap wood of Mulga is soooo fine grained and very light and clean in colour, you can still see a very thin darkish glue line at the joint. My concern being that these 'thin' lines will only be magnified under a finish.
Quite frankly I doubt very much that this offending line (we are talking thinner than half a compressed hair here) would ever be avoidable on such fine grained, clean and lightly coloured wood but experience has now taught me that Titebong is probably not the best option given the swelling it introduces to such a thin component as a veneer inlay. I understand that you can lay up thicker material when making your inlay component and then work it down with a good sharp scraper once it is glued into it's rebate, in fact this is precisely what I done. But despite my efforts, the line is still there.
I now suspect that aside from the challenge the natural contrast between glue joint and pale gold wood presents, no matter how clean you try to be, the movement introduced by the moisture in the Titebong which is placed into the rebate to accept the inlay component, wicks into the inlay components original bookmatch glue joint. In so doing, this wicking softens the joint brings with it a certain amount of contaminants from the rebate. As that joint dries out again the line is then highlighted by those residual contaminants.
Further, as those contaminants would have been pulled in to the bottom of the joint from the base of the rebate, no amount of scraping or sanding will diminish the effect. In fact, I suspect that if you were to sand away the surrounding wood, the line would become more pronounced the deeper you went. OK, so that's my own crazy theory, but lets get back to my fretboard.
So, in keeping with my sappy theme, I decide to match up the sap on a couple of narrow bits of Mulga to give the fretboard the same central gold blaze effect that is found on the above-mentioned butt wedge and back strip. This time however, instead of Titebong, I decided to use HHG for the glue joint. I know that this is a bit like shutting the gate after the horse has bolted because firstly I will be using epoxy to glue down the fretboard and this will negate any problem with water based glue, and also as there is no rebate, there will be no issue with compression swelling causing the joint to peak either.
Regardless, I am pleased to report that the glue line in the fretboard is much less visible than I imagine a Titebong glue line would have been and I reckon this indicates that HHG is a much better proposition for gluing up bookmatched inlay components and I may look at using epoxy in the rebate in future as well and touch up if needed with CA.
I guess you could just glue the bookmatch components with epoxy to begin with but I would be concerned that the clamping pressure required to obtain the very fine line I am after would starve an epoxy joint. After all, epoxy relies upon it's mechanical strength to form a bond, it must have a physical line to work, HHG and PVA on the other hand work on a molecular level.
So, what do you guys and girls think? What would you use in this circumstance? How would you go about trying to hide the glue line on such a fine grained light coloured wood.
Some images tomorrow some time maybe.
Cheers
Kim
