Revision [5010]

Last edited on 2017-09-13 11:58:40 by Vojtech Blahout
Additions:
~1) Remove the grain everywhere using a fine scraper, knife as scraper and sandpaper. Be careful on the top plate where you shouldn't use any sandpaper, just scrapers to not loose the texture of spruce. For more see the previous chapter on finishing.
Any of these procedures are best first tried out on scrapes of wood, so that you get an idea about the amounts and times involved.
If you want to avoid using sodium nitrite or are unable to obtain it, you can still expose the violin in the white to sunlight to darken naturally. Without any accelerator though, the violin takes a considerable time to darken. Exposed to direct sunlight, the stresses in the wood would be immense, humidity levels dropping which would probably result in numerous cracks. So instead of baking the violin in the sun, hang it somewhere with only indirect sunlight and wait... a couple of months. This is still possibly the least structurally invasive method, if done properly and if you have the time.
Deletions:
~1) Remove the grain everywhere using a fine scraper, knife and sandpaper. Be careful on the top plate where you shouldn't use any sandpaper, just scrapers to not loose the texture of spruce. For more see the previous chapter on finishing.
Any of these procedures are best first tried out on scrapes of wood, so that you get the idea about the amounts and times involved.
If you want to avoid using sodium nitrite or are unable to obtain it, you can still expose the violin in the white to sunlight to darken naturally. But there is a catch. Without any accelerator, the violin takes a considerable time to darken. Exposed to direct sunlight, the stresses in the wood would be immense, humidity levels dropping which would probably result in numerous cracks. So instead of baking the violin in the sun, hang the violin somewhere with only indirect sunlight and wait... a couple of months. This is still possibly the least structurally invasive method, if done properly and if you have the time.


Revision [4975]

Edited on 2016-06-06 10:32:02 by Vojtech Blahout
Additions:
~1) With the fresh /wet/ coat of sodium nitrite expose the violin to UV radiation. For wood tanning again exposure to direct sunlight or a strong UVB light is required. --- ---You have basically three options:--- --- a) Put the violin out in the sun. Get a length of firm string, tie the volute to one end and the other somewhere where the sun shines most of the day, ie a tree branch. The violin will rotate this way ensuring the proper distribution of UV. The only weak spot may be the underside where the button is, so put a sheet of aluminium foil right under with the distance of about 5 cm. The times depend on the strength of the sun. In summer a couple of hours should be sufficient. --- ---b) Use a UV mercury sun lamp, which emits strong UVB. With these precautions must be taken to avoid direct exposure of any part of your body, eyes especially. --- ---If you have the one bulb mercury lamp you will have to make sure, all parts of the violin get the same exposure. You can coat the whole violin with sodium nitrite at once though. Then expose different parts. The violin can be dry during exposure but higher humidity levels either in the violin /freshly coated/ or in the air help speed up the oxidative process of tanning.--- ---For a **250 Watt** mercury UV lamp about **20-30 minutes** from **40 cm** distance are enough, assuming the violin is still damp from the solution. --- ---You will need to rotate the violin every **30 minutes** to cover all angles. Don't forget to turn off the lamp before you do this, or wear UV protective glasses. It takes a whole day to tan a violin this way. --- ---c) UV cabinet. The black light UVA-B tubes used in varnish curing are usually much slower in tanning so you will need the white ones which don't block out most of the UVB. --- --- Tanning times for the whole instrument may vary from hours to days depending on the kind of tubes you are using. Watch for humidity, see the varnishing section.
Deletions:
~1) With the fresh /wet/ coat of sodium nitrite expose the violin to UV radiation. For wood tanning again exposure to direct sunlight or a strong UVB light is required. --- ---You have basically three options:--- --- a) Put the violin out in the sun. Get a length of firm string, tie the volute to one end and the other somewhere where the sun shines most of the day, ie a tree branch. The violin will rotate this way ensuring the proper distribution of UV. The only weak spot may be the underside where the button is, so put a sheet of aluminium foil right under with the distance of about 5 cm. The times depend on the strength of the sun. In summer a couple of hours should be sufficient. --- ---b) Use a UV mercury sun lamp, which emits strong UVB. With these precautions must be taken to avoid direct exposure of any part of your body, eyes especially. --- ---If you have the one bulb mercury lamp you will have to make sure, all parts of the violin get the same exposure. You can coat the whole violin with sodium nitrite at once though. Then expose different parts. The violin can be dry during exposure but higher humidity levels either in the violin /freshly coated/ or in the air help speed up the oxidative process of tanning.--- ---For a **250 Watt** mercury UV lamp about **20-30 minutes** from **40 cm** distance are enough, assuming the violin is still damp from the solution. --- ---You will need to rotate the violin every **30 minutes** to cover all angles. Don't forget to turn off the lamp before you do this, or wear UV protective glasses. It takes a whole day to tan a violin this way. --- ---c) UV cabinet. The black light UVA-B tubes used in varnish curing are usually much slower in tanning so you will need the white ones which don't block out most of the UVB. Plans for the UV cabinet can be found in [[UV cabinet building|UV cabinet building]]. In this cabinet the UV exposure is more even so you don't need to rotate the violin making the process automatic. This cabinet can also be used for varnish curing but you may want to use weaker tubes for that. --- --- Tanning times for the whole instrument may vary from hours to days depending on the kind of tubes you are using. Watch for humidity, see the varnishing section.


Revision [4958]

Edited on 2016-06-04 12:15:15 by Vojtech Blahout
Additions:
~1) With the fresh /wet/ coat of sodium nitrite expose the violin to UV radiation. For wood tanning again exposure to direct sunlight or a strong UVB light is required. --- ---You have basically three options:--- --- a) Put the violin out in the sun. Get a length of firm string, tie the volute to one end and the other somewhere where the sun shines most of the day, ie a tree branch. The violin will rotate this way ensuring the proper distribution of UV. The only weak spot may be the underside where the button is, so put a sheet of aluminium foil right under with the distance of about 5 cm. The times depend on the strength of the sun. In summer a couple of hours should be sufficient. --- ---b) Use a UV mercury sun lamp, which emits strong UVB. With these precautions must be taken to avoid direct exposure of any part of your body, eyes especially. --- ---If you have the one bulb mercury lamp you will have to make sure, all parts of the violin get the same exposure. You can coat the whole violin with sodium nitrite at once though. Then expose different parts. The violin can be dry during exposure but higher humidity levels either in the violin /freshly coated/ or in the air help speed up the oxidative process of tanning.--- ---For a **250 Watt** mercury UV lamp about **20-30 minutes** from **40 cm** distance are enough, assuming the violin is still damp from the solution. --- ---You will need to rotate the violin every **30 minutes** to cover all angles. Don't forget to turn off the lamp before you do this, or wear UV protective glasses. It takes a whole day to tan a violin this way. --- ---c) UV cabinet. The black light UVA-B tubes used in varnish curing are usually much slower in tanning so you will need the white ones which don't block out most of the UVB. Plans for the UV cabinet can be found in [[UV cabinet building|UV cabinet building]]. In this cabinet the UV exposure is more even so you don't need to rotate the violin making the process automatic. This cabinet can also be used for varnish curing but you may want to use weaker tubes for that. --- --- Tanning times for the whole instrument may vary from hours to days depending on the kind of tubes you are using. Watch for humidity, see the varnishing section.
Deletions:
~1) With the fresh coat of sodium nitrite expose the violin to UV radiation. For wood tanning again exposure to direct sunlight or a strong UVB light is required. --- ---You have basically three options:--- --- a) Put the violin out in the sun. Get a length of firm string, tie the volute to one end and the other somewhere where the sun shines most of the day, ie a tree branch. The violin will rotate this way ensuring the proper distribution of UV. The only weak spot may be the underside where the button is, so put a sheet of aluminium foil right under with the distance of about 5 cm. The times depend on the strength of the sun. In summer a couple of hours should be sufficient. --- ---b) Use a UV mercury sun lamp, which emits strong UVB. With these precautions must be taken to avoid direct exposure of any part of your body, eyes especially. --- ---If you have the one bulb mercury lamp you will have to make sure, all parts of the violin get the same exposure. You can coat the whole violin with sodium nitrite at once though. Then expose different parts. The violin can be dry during exposure but higher humidity levels either in the violin /freshly coated/ or in the air help speed up the oxidative process of tanning.--- ---For a **250 Watt** mercury UV lamp about **20-30 minutes** from **40 cm** distance are enough, assuming the violin is still damp from the solution. --- ---You will need to rotate the violin every **30 minutes** to cover all angles. Don't forget to turn off the lamp before you do this, or wear UV protective glasses. It takes a whole day to tan a violin this way. --- ---c) UV cabinet. The black light UVA-B tubes used in varnish curing are usually much slower in tanning so you will need the white ones which don't block out most of the UVB. Plans for the UV cabinet can be found in [[UV cabinet building|UV cabinet building]]. In this cabinet the UV exposure is more even so you don't need to rotate the violin making the process automatic. This cabinet can also be used for varnish curing but you may want to use weaker tubes for that. --- --- Tanning times for the whole instrument may vary from hours to days depending on the kind of tubes you are using. Watch for humidity, see the varnishing section.


Revision [4955]

Edited on 2016-04-09 20:12:39 by Vojtech Blahout
Additions:
<div class='obrazek' style='height: 2900px; width: 220px;'></div>
~1) With the fresh coat of sodium nitrite expose the violin to UV radiation. For wood tanning again exposure to direct sunlight or a strong UVB light is required. --- ---You have basically three options:--- --- a) Put the violin out in the sun. Get a length of firm string, tie the volute to one end and the other somewhere where the sun shines most of the day, ie a tree branch. The violin will rotate this way ensuring the proper distribution of UV. The only weak spot may be the underside where the button is, so put a sheet of aluminium foil right under with the distance of about 5 cm. The times depend on the strength of the sun. In summer a couple of hours should be sufficient. --- ---b) Use a UV mercury sun lamp, which emits strong UVB. With these precautions must be taken to avoid direct exposure of any part of your body, eyes especially. --- ---If you have the one bulb mercury lamp you will have to make sure, all parts of the violin get the same exposure. You can coat the whole violin with sodium nitrite at once though. Then expose different parts. The violin can be dry during exposure but higher humidity levels either in the violin /freshly coated/ or in the air help speed up the oxidative process of tanning.--- ---For a **250 Watt** mercury UV lamp about **20-30 minutes** from **40 cm** distance are enough, assuming the violin is still damp from the solution. --- ---You will need to rotate the violin every **30 minutes** to cover all angles. Don't forget to turn off the lamp before you do this, or wear UV protective glasses. It takes a whole day to tan a violin this way. --- ---c) UV cabinet. The black light UVA-B tubes used in varnish curing are usually much slower in tanning so you will need the white ones which don't block out most of the UVB. Plans for the UV cabinet can be found in [[UV cabinet building|UV cabinet building]]. In this cabinet the UV exposure is more even so you don't need to rotate the violin making the process automatic. This cabinet can also be used for varnish curing but you may want to use weaker tubes for that. --- --- Tanning times for the whole instrument may vary from hours to days depending on the kind of tubes you are using. Watch for humidity, see the varnishing section.
Wood tanning by exposure to UV radiation is inherently a destructive process so it should be practiced with caution. The desirable darkening of the wood is caused by the uppermost layer of the wood getting oxidized and degraded. The UV light produces ozone, which reacts with the nitrogen gas present in the air and forms nitrous oxygen. The nitrous oxygen then "burns" /oxidizes/ the wood leaving it slightly acid.
2. Let it stand for a couple of days, up to five, or until you are satisfied with the color.
Deletions:
<div class='obrazek' style='height: 2800px; width: 220px;'></div>
~1) With the fresh coat of sodium nitrite expose the violin to UV radiation. For wood tanning again exposure to direct sunlight or a strong UVB light is required. --- ---You have basically three options:--- --- a) Put the violin out in the sun. Get a length of firm string, tie the volute to one end and the other somewhere where the sun shines most of the day, ie a tree branch. The violin will rotate this way ensuring the proper distribution of UV. The only weak spot may be the underside where the button is, so put a sheet of alluminium foil right under with the distance of about 5 cm. The times depend on the strength of the sun. In summer a couple of hours should be sufficient. --- ---b) Use a UV mercury sun lamp, which emits strong UVB. With these precautions must be taken to avoid direct exposure of any part of your body, eyes especially. --- ---If you have the one bulb mercury lamp you will have to make sure, all parts of the violin get the same exposure. You can coat the whole violin with sodium nitrite at once though. Then expose different parts. The violin can be dry during exposure but higher humidity levels either in the violin /freshly coated/ or in the air help speed up the oxidative process of tanning.--- ---For a **250 Watt** mercury UV lamp about **20-30 minutes** from **40 cm** distance are enough, assuming the violin is still damp from the solution. --- ---You will need to rotate the violin every **30 minutes** to cover all angles. Don't forget to turn off the lamp before you do this, or wear UV protective glasses. It takes a whole day to tan a violin this way. --- ---c) UV cabinet. The black light UVA-B tubes used in varnish curing are usually much slower in tanning so you will need the white ones which don't block out most of the UVB. Plans for the UV cabinet can be found in [[UV cabinet building|UV cabinet building]]. In this cabinet the UV exposure is more even so you don't need to rotate the violin making the process automatic. This cabinet can also be used for varnish curing but you may want to use weaker tubes for that. --- --- Tanning times for the whole instrument may vary from hours to days depending on the kind of tubes you are using. Watch for humidity, see the varnishing section.
Wood tanning by exposure to UV radiation is inherently a destructive process so it should be practiced with caution. The desirable darkening of the wood is caused by the uppermost layer of the wood getting oxidized and degraded. The UV light produces ozone, which reacts with the nitrogen gas present in the air and forms nitrous oxygen. The nitrous oxygen then "burns" the wood leaving it slightly acid.
2. Let it stand for a couple of days, up to five, or until you satisfied with the color.


Revision [4954]

Edited on 2016-04-09 19:41:25 by Vojtech Blahout
Additions:
"">>Prior to varnishing, you should set up the violin in the white and make sure it is playable, and it doesn't have any buzzes, which could require reopening of the instrument. Only if you are satisfied with the sound, should you proceed to prepare the surfaces for varnishing.
Deletions:
"">>Prior to varnishing, you should set up the violin in the white and make sure it is playable, and it doesn't have any buzzes, which could require reopening of the instrument. If you are satisfied with the sound, proceed to prepare the surfaces for varnishing.


Revision [4953]

Edited on 2016-04-09 19:40:25 by Vojtech Blahout
Additions:
"">>Prior to varnishing, you should set up the violin in the white and make sure it is playable, and it doesn't have any buzzes, which could require reopening of the instrument. If you are satisfied with the sound, proceed to prepare the surfaces for varnishing.
==Preparing the wood surface==
Deletions:
"">>==Preparing the wood surface==


Revision [4928]

Edited on 2016-03-18 00:35:21 by Vojtech Blahout
Additions:
~1) **4%** Sodium nitrite, **50 ml**. To prepare, weigh **50 gr** of water and add **2 gr** of Sodium nitrite.
2. **26%** ammonia /laundry grade/
Deletions:
~1) 4% Sodium nitrite, **50 ml**. To prepare, weigh **50 gr** of water and add **2 gr** of Sodium nitrite.
2. 26% ammonia /laundry grade/


Revision [4927]

Edited on 2016-03-18 00:35:07 by Vojtech Blahout
Additions:
2. 26% ammonia /laundry grade/
Deletions:
2. 26 percent strong ammonia /laundry grade/


Revision [4926]

Edited on 2016-03-18 00:34:06 by Vojtech Blahout
Additions:
<div class='obrazek' style='height: 2800px; width: 220px;'></div>
~1) Put a coat of **4%** sodium nitrite on the violin. Make sure the coat is even and there are no drops left as these would make the wood darker. Don't forget to apply some under the fingerboard as well. --- ---Sodium nitrite accelerates what normally happens when you put the violin out in the sun. It helps oxidize the outer layers of the wood making it look darker.
~1) With the fresh coat of sodium nitrite expose the violin to UV radiation. For wood tanning again exposure to direct sunlight or a strong UVB light is required. --- ---You have basically three options:--- --- a) Put the violin out in the sun. Get a length of firm string, tie the volute to one end and the other somewhere where the sun shines most of the day, ie a tree branch. The violin will rotate this way ensuring the proper distribution of UV. The only weak spot may be the underside where the button is, so put a sheet of alluminium foil right under with the distance of about 5 cm. The times depend on the strength of the sun. In summer a couple of hours should be sufficient. --- ---b) Use a UV mercury sun lamp, which emits strong UVB. With these precautions must be taken to avoid direct exposure of any part of your body, eyes especially. --- ---If you have the one bulb mercury lamp you will have to make sure, all parts of the violin get the same exposure. You can coat the whole violin with sodium nitrite at once though. Then expose different parts. The violin can be dry during exposure but higher humidity levels either in the violin /freshly coated/ or in the air help speed up the oxidative process of tanning.--- ---For a **250 Watt** mercury UV lamp about **20-30 minutes** from **40 cm** distance are enough, assuming the violin is still damp from the solution. --- ---You will need to rotate the violin every **30 minutes** to cover all angles. Don't forget to turn off the lamp before you do this, or wear UV protective glasses. It takes a whole day to tan a violin this way. --- ---c) UV cabinet. The black light UVA-B tubes used in varnish curing are usually much slower in tanning so you will need the white ones which don't block out most of the UVB. Plans for the UV cabinet can be found in [[UV cabinet building|UV cabinet building]]. In this cabinet the UV exposure is more even so you don't need to rotate the violin making the process automatic. This cabinet can also be used for varnish curing but you may want to use weaker tubes for that. --- --- Tanning times for the whole instrument may vary from hours to days depending on the kind of tubes you are using. Watch for humidity, see the varnishing section.
Deletions:
<div class='obrazek' style='height: 2500px; width: 220px;'></div>
~1) Put a coat of 4% sodium nitrite on the violin. Make sure the coat is even and there are no drops left as these would make the wood darker. Don't forget to apply some under the fingerboard as well. --- ---Sodium nitrite accelerates what normally happens when you put the violin out in the sun. It helps oxidize the outer layers of the wood making it look darker.
~1) With the fresh coat of sodium nitrite expose the violin to UV radiation. For wood tanning again exposure to direct sunlight or a strong UVB light is required. --- ---You have basically three options:--- --- a) Put the violin out in the sun. Get a length of firm string, tie the volute to one end and the other somewhere where the sun shines most of the day, ie a tree branch. The violin will rotate this way ensuring the proper distribution of UV. The only weak spot may be the underside where the button is, so put a sheet of alluminium foil right under with the distance of about 5 cm. The times depend on the strength of the sun. In summer a couple of hours should be sufficient. --- ---b) Use a UV mercury sun lamp, which emits strong UVB. With these precautions must be taken to avoid direct exposure of any part of your body, eyes especially. --- ---If you have the one bulb mercury lamp you will have to make sure, all parts of the violin get the same exposure. You can coat the whole violin with sodium nitrite at once though. Then expose different parts. The violin can be dry during exposure but higher humidity levels either in the violin /freshly coated/ or in the air help speed up the oxidative process of tanning.--- ---For a 250 Watt mercury UV lamp about 20-30 minutes from 40 cm distance are enough, assuming the violin is still damp from the solution. --- ---You will need to rotate the violin every 30 minutes to cover all angles. Don't forget to turn off the lamp before you do this, or wear UV protective glasses. It takes a whole day to tan a violin this way. --- ---c) UV cabinet. The black light UVA-B tubes used in varnish curing are usually much slower in tanning so you will need the white ones which don't block out most of the UVB. Plans for the UV cabinet can be found in [[UV cabinet building|UV cabinet building]]. In this cabinet the UV exposure is more even so you don't need to rotate the violin making the process automatic. This cabinet can also be used for varnish curing but you may want to use weaker tubes for that. --- --- Tanning times for the whole instrument may vary from hours to days depending on the kind of tubes you are using. Watch for humidity, see the varnishing section.


Revision [4905]

The oldest known version of this page was created on 2016-02-26 11:10:42 by Vojtech Blahout