Violin Forum/Message Board

[John Cadd]

The only design of Mould I ever see people use is the internal kind. Many makers say they do things the Strad way. I thought he used the external mould . ( Maybe Vuillaume was the main user of the external mould to make accurate copies of established violins. There is no trace of external moulds in the Sacconi book showing all Strad`s bits and pieces ).The purpose of the external shape is to maintain the exact rib shape outline and make it simple to match the finished plate which will already have the purfling inserted .If you use an internal mould and a finished plate (plus the purfling ) there is going to be a clash when the glue up job starts . I thought the original Guarnerius models used the internal mould and Strads used the external moulds . Maybe the Heron Allen book was misleading . Does anyone else still do the purfling after constructing the box ? The outline and purfling will follow the outline better that way without fighting with the ribs to make them line up . Maybe competition judges are unconsciously restricting the way violins are made today .

[John Cadd]

I had to look up the Images to see what modern versions looked like. The holes surrounding the tips of the corners don`t allow much room to trim the corner joint. Also it looks as if the blocks are added to the ribs instead of the other way round . The sides and corner joins are meant to be more regular and straight using the outside mould but I can`t say it adds up just yet . I thought the corner tips had to be pressed tight into position to make sure they were exactly where they had to be . I will have to make one myself and see what happens . But this design had the reputation of turning out accurate copies where the inside mould left shape details more flexible .

[mikemolnar]

I have both kinds of molds (moulds). I prefer the internal by far. If you make sure that the ribs are snug to the form and stand perpendicularly, you can't go wrong. My external mold, the Iron Maiden, is used to hold a garland that is removed from the internal mold, but waiting for the plates to be ready. Also, I use this external mold if the garland seems to misbehave, namely drifts in shape.

In any case, the internal mold also easier to make and alter for adjustments.

Stay Tuned.
Mike

[L P Reedy]

I'm with Mike, except that in my case I have no use whatever for an outside mold. I'm confident that Stradivari never heard of an outside mold, regardless of what you may have thought Heron-Allen said. It would be totally inconsistent with Strad's presumed working methods, in addition to the museum collection of his internal molds.

[John Cadd]

The other reason I asked about molds was to compare the solid molds with the much thinner types that leave much of the inside rib surface exposed.Does the solid type maintain the final volume in a better way ? A straight edge laid along the surface will quickly show up any deviation from the planned measurements . The solid type flat surfaces can be maintained with car body repair resin and sanded flat if any edges become worn down.

[L P Reedy]

I do use full thickness molds, not always solid, but not because I care about the volume because I don't. I do it simply because, with my methods and handling, the ribs experience much less damage during construction. Others have their own ways of doing things.

[L P Reedy]

I do use full thickness molds, not always solid, but not because I care about the volume because I don't. I do it simply because, with my methods and handling, the ribs experience much less damage during construction. Others have their own ways of doing things.

[John Cadd]

Reedy I have in the past used small wedges to ensure the tightness of glue joints .That causes slight dents in the rib surfaces . I found I could cure that by laying 3 thin , damp folds of cotton on them and rolling the shaft of a soldering tool (as if ironing a tiny shirt ) for a few seconds. The dent just goes away without a blemish . Good to know maple is so obliging . The soldering tool has no bit fitted in it .The end is just over one centimetre thick.