Hope you can join us today in the workshop at 1pm - cup of tea (beverage of your choosing) is required.
It is traditional to raise a mug after we glue on the back...make sure to get yours ready!
Measure twice, cut once...
Reference the discussion today about sealing the inside of instruments and why it's done on carved arch tops and not on flat tops. I've got some background in violin making and it's a topic which is frequently talked about ie why some people do it and what to use.
Historically it was used on carved type instruments because they don't have a centre joining strip as reinforcement and always used water based hot hide glue to join the pieces, which is prone to fail in hot damp conditions. So sealing the inside gives protection from glue failure. Joint separation on old instruments that haven't been sealed is quite common. I've worked on instruments that were only held together by the varnish.
Another factor is the carving construction method, which if you start with quarter sawn timber and carve an arch creates a situation at the top of the arch where damp is liable to change the arching shape. My evidence for saying this is a violin I built a few years ago where I experimented with a water based stain (the German method) prior to varnishing, which caused a significant change in shape and string height as it swelled the spruce top. I had to wait a while for it to dry out before varnishing and fitting strings. So again sealing is useful. One weakness in this argument is water based sealers such as Aquacoat which I believe Mark uses, however they are quick drying and don't put a lot of moisture into the wood.
People still debate about what the old masters used for sealing and the strongest opinion seems to be Casein which is some form of milk protein. Experts think it improves the sound but given that sound is very subjective it's probably what they want to hear. Moving on to the 21st Century I'm sure there are modern products which are much better.
Some people call me a tool, others are less complimentary. Tools being useful things.
Wow @rocknroller912 - interesting stuff!
Do you make many violins?
Online guitar making courses – guitarmaking.co.uk
tv101
I haven't made a lot of new violins as there isn't much demand but that's not unusual. I've spoken to full time professional makers who only do repairs or take part made Chinese instruments and rework them for a better sound.
Ive done lots of repairs over the last 30 years, some on very old instruments which involves and element of conservation and making new work look old. The woodwork is usually the easy bit with colour matching being the most challenging.
Bow making is fun and more of a black art than tap tuning acoustic fronts and backs.
Some people call me a tool, others are less complimentary. Tools being useful things.
Casein which is some form of milk protein.
Is this why Strads smell of cheese? 🤣 🤣
In the world of veneering keeping glue lines, ie moisture, balanced on both sides of a panel are key to it staying flat so it has always struck me as odd that guitars would be lacquered/sealed on one side and left open to humidity changes on the other. Maybe on such a thin panel the moisture levels reach equilibrium throughout the thickness of the wood before any excessive stresses can form.
Darren
My Strat doesn't smell of cheese.... It smells of sweat and stale beer......
It's not just your Strat @e-den-hertog
😆
Online guitar making courses – guitarmaking.co.uk
Online guitar making courses – guitarmaking.co.uk
Is this why Strads smell of cheese?
Probably sweaty fingers. Some guitar techs charge extra for cleaning before they will start work.
Interesting point about veneer I found this out the hard way the first time I tried to use it. Last year I was following a Spanish guitar maker on utube and his theory is that when gluing international bracing on front and back, the outside of the bracing should be dampened to equalise the tension in the wood.
Some people call me a tool, others are less complimentary. Tools being useful things.