Rosette Defect Filling

[bearskindrum]

Hi All, I have an issue with my wooden rosette which had just become aparent... the Redwood burl rosette which I have inlaid has collapsed in slightly in a small area about 5mm x 5mmm?? This was probably due to the fact that the rosette was made up of 2 x 0.75mm thick veneers laminated together and a possible air bubble between the two pieces???the good news is athat apart from the collapse, which is only about 1mm deep, the rosette is intact so my question is which transparent glue to fill this with? Epoxy? Super Glue? I will am french polishing overtop of rosette/top and obviously want the repair to look good because its a Hi Viz area....

Regards Mark

[tippie53]

we need pictures
that will help

[B. Howard]

I typically handle situations like this with a hot knife and a burn in clear burn in stick. CA is out because you run a high risk of discoloring the spruce. As for epoxies, SB 112 from System 3 is the only one I am aware of that is optically clear enough to fill a void under FP and not jump right out.

[bearskindrum]

Hi John, images attached. The front on view shows the rosette and that the burl veneer is indeed intact the low image with side lighting shows the degree of collapse and some old shellac and glue that I have cleaned off...the collapse looks worse than it is I think but I have taken the photo to deliberately highlight the problem, I think with the right transparent resin/glue a good repair could be done....so what do you think I should do?

Regards Mark

[bearskindrum]

Hi Brian not sure what you mean by "hot knife and clear burn in stick"?? the spruce as you can see from the photos is not involved.... just the burl in the rosette itself.

Regards Mark

[B. Howard]

Even though the spruce is separated by a purfling the CA stands a chance of wicking through and turning the spruce an ugly green that will be permanent.

A burn in repair is done with a hot knife and a stick of resin made for the job. They make electric hot knives or you can do as I do and use a bunsen burner or a propane torch to heat a knife. I use a stainless butter knife with the end cut off. Behlens has stick of filler, #B320-012 is the clear. Stew mac has a complete kit and may still sell individual sticks but you will need to call them. I show a bit about the process in this thread here.
viewtopic.php?f=48&t=5824&hilit=a+pair&start=60

[tippie53]

can you get a better pic of the damaged area
I appears that you didn't get the rosette seated properly or as you sanded you built up some heat that popped the wood up .
I can't say for sure but it does look like a clean separation. You may be able to pull that up with some tape. Then I would back shim and reglue or epoxy but you still need a backer to get the wood flat. I do think it is salvageable.

[bearskindrum]

Hi Brian, thanks for the explanation. The burn in method looks good but unfortunately no one down here sells the sticks or other bits and while could get it from StewMacs I have opted to go with using shellac to fill the defect, mainly because I have no experience with the shella stick method as you described or indeed the epoxy superglue methods and I don't want to risk the wifes guitar build with untried techniques to say nothing of the rare woods that this is being made out of!
It was a bit tedeous... I made up a 3LB cut of the blonde shellac that I had been using for the finish as a 1Lb cuts and spent about 2-3 hours of playing with the shellac while still soft and steering it into the defect and then layering and building it up and steering some more until it had completely over filled the void and surrounding area. Once its rock hard I will level with the top and then continue Frenchpolishing the top and I think that the repair should look very good and hopefully not too noticable, if at all.

Regards Mark

[bearskindrum]

Hi John thanks for the ideas... as the rosette had sunken, not popped up, I was not game to try and pull the 0.7mm lamination up and then backfill with epoxy through an incision in either the medial or lateral side( Y'all can probably tell I work at a hospital) of the rosette between the BWB purfling and the burled redwood veneer...call me chicken if you wants to ...I have opted for the shellac filling repair, as above in my reply to Brian, which will hopefully give me a good aesthetic result and is the medium that I feel safest working with at this stage...
Thanks again John... you and the Alturistic nature of the Forum members here is a constant source of inspiration...

Regards Mark