Violin Forum/Message Board

[M.Lange]

Here is what I do to test the strength of the joint:
I do a few passes with the plane and try to pull the shavings apart.
If it separates at the joint rather than anywhere along the grain, it probably is better to start again...

Matthias

[kel]

nice to hear your suggestion, would try this the next day

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this morning planed the joint and checked, looks fine basically
the imperfection also lies on one end and doesn't matter as i'd cut away after drawing the outline
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Newbie Maker Kelvin

[Dave Chandler]

Matthias, good suggestion.

I just joined some fresh back and top wood. Some AAA billets. I did a rubbed/but not clamped back and the outcome was excellent, but had to recut the spruce top three times ending up doing a rubbed then clamped joint. Each time, it appeared to be a perfect joint before gluing up. Not sure why the maple would be so easy and the spruce soo difficult this time.

I'm working in my shop where temperature is only about 60 deg and humidity is only about 15%, so I put the wood in the kitchen oven at 120 for an hour or so, wrap it and take it down to the shop and glue and clamp it before it loses its warmth. Maybe this is my last till spring. Maybe I need to heat it to 140 or so. Cool work environment could be the reason its become difficult to glue up, maybe the maple cools more slowly than the spruce, dunno.
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Dave in the Blue Ridge
Southern Violin Association

"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill

"I took the road less travelled, and now I don't know where I am." Marco Polo

[M.Lange]

[kel]

i did rubbed joint for my spruce, so far in hollowing the inside and carving the outer, spruce doesn't separate

still i have some worry on possible spruce separation and i intentionally leave the spruce thicker around the f hole area
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Newbie Maker Kelvin

[kel]

Is it a MUST NOT to use sand paper for either top spruce or maple back?
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Newbie Maker Kelvin

[Jack H.]

[kel]

Jack, my spruce already jointed and is being hollowed
but i don't have finger plane at this moment

at present my trouble is how to plane the curvature along the outline especially the upper bout
the thickness i got now is about 5mm and still a lot to fine adjust

just wonder whether to use sand paper before my finger plane arrives

[/img] http://www.flickr.com/photos/32897962@N03/3070771755/in/photostream/ [/img]
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Newbie Maker Kelvin

[Mikes]

Kel,
It looks like your outline is still rough, if so use a half round bastard file to bring the outline right down to the line (split the line) this can be done before you do any arching, also make sure you figure out your corners before you file to the line, leave them slightly long but to the finished width. And from your picture it looks like you have a ways to go on hollowing your plate, I use a gouge to remove the material to within about 1.5 - 2 mm, then use the finger plane. Don't use sand paper any where that you will later use cutting tools or a scraper on as the sand paper will leave broken off abrasive lodged into the wood which will then dull your tools. Keep at and you'll end up with an instrument to be proud of!

Mike S

[Mikes]

Kel,
It looks like your outline is still rough, if so use a half round bastard file to bring the outline right down to the line (split the line) this can be done before you do any arching, also make sure you figure out your corners before you file to the line, leave them slightly long but to the finished width. And from your picture it looks like you have a ways to go on hollowing your plate, I use a gouge to remove the material to within about 1.5 - 2 mm, then use the finger plane. Don't use sand paper any where that you will later use cutting tools or a scraper on as the sand paper will leave broken off abrasive lodged into the wood which will then dull your tools. Keep at and you'll end up with an instrument to be proud of!

Mike S

[kel]

Thanks Mike

I deliberately leave a safety margin beyond the true outline to allow for minor error.

I hollow the spruce with little bit with gouge and mainly (over 96%) with 2 small size planes.
I can get the spruce thinner but i would do it in safe mode so as not to get a hole
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Newbie Maker Kelvin

[kel]

with limited budget, I possibly would order one finger plane only : round bottom 25mm with 8mm blade

can i have some advice from here before i place order?
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Newbie Maker Kelvin

[Dave Chandler]

Before you get too much further, take your assembled rib garland and trace it onto the back, then add another line inside by 1mm, sketch in block areas, and then graduate right up to those lines. If you haven't put the garland together, you can't know where your edges are going to be.

I use a small gouge, then a scraper with a tight but rounded corner (about a 2mm radius) to get up to those lines.
_________________
Dave in the Blue Ridge
Southern Violin Association

"Success is the ability to go from one failure to the next with no loss of enthusiasm" Winston Churchill

"I took the road less travelled, and now I don't know where I am." Marco Polo

[kel]

hi
i am still working on my first violin

hollowing the back is definitely a hard job

any suggestion to make it less difficult?

just found a unpleasant measurement :
width of my first violin
upper : 173
middle : 118
lower : 212

can it be tolerated?
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Newbie Maker Kelvin

[violinarius]