Thread: Acoustic build no 1

nice wood
look foward to seeing the progress

Good start Rob, I'll be keeping an eye on this one.

photo 3 cherry, what are you going to use this for.? a bit of headstock.
As from what I see close up in the photo it is full of cracks.
Bob

Originally Posted by auscab

I read the books to the point that they didn't make any more sense, I couldn't fit any more info in and seemed to be going around in circles,

I started months back and thought I am not going to post it till I get past the side bending stage,this was the point I thought I may get stuck on.

I am building off the Kinkead plan but am doing a bolt on Cumpiano style neck join,the shape was changed ,The Kauri came from an old counter top which I cut 5 tops out of ,I was going around with a block plane shaveing the ends of any kauri I had and it was all wrong ,till I got to the bigest bit I had ,the end grain was perfect, there were knots and nail holes to avoid

left picture is the counter top
Next ,four of the tops that came from it with some Cherry Ballart
Next a close up of the cherry ,it's about 100 x 100 mm
Next the Blackwood sides and back
This blackwood is impossible to hand plane,so I got a freind to pass it through his drum sander

Thank's for comment's gents . Yes Bob I
was thinking of the cherry for a bit of veneer
for the head stock,but this bit may be a bit
small ,I liked the picture so much I put it on
anyway, but the cherry may be for no 2 .

One of the pine tops and blackwood are for
my no 1 and haven't finalized finger board and
head stock veneer decision yet,but will probably
go with ebony.

pictures from left are
first two, sorting out the shape that then went on
to a template which was flipped to get the full shape
that went on to make the plywood mould.

That big flush trimming bit was a beauty.

The dowel I turned up has 40 grit paper glued on it

The dotted lines in pic 2 are from dreadnought size
guitars from Japan that I own,and the other lines
show how I am trying to get a more early look that
also will fit the Kinkead plan.

cheers Rob

Love that shape, the sound is going to be awesome.

On to the sound board ,while I also try plane down to thickness that blackwood.

This was going to be an interesting challenge,laying in ebony stringing around the sound hole.

The making of the pin attachment for my trimmer so it could do wee circles worked out well , after a trial with the steel pin riveted on to the brass plate failed, I had to braze it on and the circles went well.

Then I started to lay in the ebony on the outer ring, snap, hammer back in , snap and so on ,the snaps are the ebony breaking about four times.after the first two I soaked it and heated it,the grain in the ebony I had ,ran at about 70 deg in spots, the second strip went a bit better exept it came up a bit short, and I had to fit approx 25 mm in at the top,the breaks and join are visible,

I had intended for the larger ring to have boxwood, then ebony boxwood squares about 2.8 x 2.8 , then boxwood, I prepared it all but this started going to pieces every 10mm.I got to admit I was swearing at my sounboard guy's,ha ha. so I put it to one side for a while, and decided on a more simple approach.

The pictures tell the story,a kauri ring was routed from one of my
"NOW SCRAP "sound boards in the first picture ,that my thickneser "ATE "the end off,
that was when I was pushing my luck at about 3.2 mm,

wont try that again!

So the ring went in, scraped back after it dried, I ground a punch to match the ebony end grain , divided up 24 points and with a few taps at each point glued in the ebony squares.

The sound board was laying on a clean bit of 19mm ply which is quite soft stuff and I was lucky none of them went right through,when I sanded back the 24 lumps on the back I could see the black ebony was very close, so if I did it again I would go a little bit easy with the hammer, but would also transfer the sound board to a harder surface,like the cast iron top of my table saw.

no cheers Rob.

I just did 5 soprano ukulele rosettes with abalone surrounded by ebony, 2 1/2" diameter.
Never again
I was trying to use what I had on hand rather than ordering in some black fibre.....

I will have to get some ,is it the same material that is used for the binding or purfling?and isn't it just a plastic of some sort?

Yeah purfling material, not plastic, don't know exactly

Originally Posted by auscab

I will have to get some ,is it the same material that is used for the binding or purfling?and isn't it just a plastic of some sort?

Its not plastic.....its paper based. In some circles I believe its called fish paper. Regardless..it bends a whole lot easier than ebony!!

The first time bending on my fist side went well, it took me about one and a half hours, the second side went a bit wonky and took about four hours to get right,I found that bending and trying to fit to the mould was throwing me out a bit,so I drew a line off the template and bending to that line,like the Cumpiano method suggests, made it much easier to see where I was out, I had developed a twist in the side and figuring out how to fix it was way harder than just a change in direction,there is also a fair amount of charring and I dont know if' it's going to sand out? but I do know some of the black is from iron oxide stains from my steel bending iron, and a wipe with oxalic acid sort's that out quick. cheers Rob.

Originally Posted by auscab

I found that bending and trying to fit to the mould was throwing me out a bit,so I drew a line off the template and bending to that line,like the Cumpiano method suggests, made it much easier to see where I was out, I had developed a twist in the side and figuring out how to fix it was way harder than just a change in direction,there is also a fair amount of charring and I dont know if' it's going to sand out? but I do know some of the black is from iron oxide stains from my steel bending iron, and a wipe with oxalic acid sort's that out quick. cheers Rob.

Rob,

Using a template as a guide when bending is definitely easier then using an external mould. I use the half template (made from 3mm MDF) I use to set out top and back....I have it clamped to the edge of my bench and refer to it frequently during a bending session.

When bending I do the waist first, then the lower bout and finally the upper bout.

Burn marks..if they're on the inside of the guitar don't get to worried about them. If on the outside then they should sand out. If burning is an issue then look at temperature of the iron and how much time your spending holding the wood against the iron and also how much water your spraying on the wood. I tend to keep the wood moving over the iron while bending rather than holding it stationary.

1 1/2 hours to bend your first side.....you did well.

Hi Martin, the first side was good fun, the second, I was a bit tired , and ended stopping when it started to go wrong and went home ,picked it up the next morning to finish it off,in some places it has .75 mm cup with a guess, heated and clamped with a caul but it did not go out,it should sand out a bit,


Of all the methods for bending a side, has any one ever seen anyone do it like bending a plank for a side of a boat? or a back for a windsor chair ? it could be steamed in a pipe, pulled out, and a sand bag clamped at the waist, then the upper and lower bout wrapped and clamped,with two men it could be finished in one minute ?
Or make a box to steam it in ,pull it out ,clamp one end ,then sand bag ,then clamp the other end over a half mould?