silk backing

[Sparky Buckwheat]

Jayman,

I am relatively new to bowmaking (2013), however I was drawn in to silk backing as a result of the mention of Hickman using it back in the 1930's in TBB1.  I then recieved a number of bolts of silk noil fabric (woven, unrefined short silk fibers).  It seemed very strong, although it does stretch.  When reading the vague discription in TBB1, it mentions Hickman somehow stretched the silk into tension and then applied the bow to it with some sort of glue.  I did some thinking and developed a rack that I can stretch the silk into tension and lay the bow on.  It requires packing tape as I use G2 epoxy (epoxy does not stick to packing tape, although I still need to pry the bow off the jig with some force).  I did a posting on Trad Gang back in November that shows my basic setup and some of the early results.  http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=012213;p=1#000005  In that thread, it shows a backing strip that actually pulled into reflex after it came off the jig with the silk.  This leads me to believe that silk CAN provide more than just "some protection" to a back if it is applied correctly and a good fabric is used.  I really need to do further research but I am too busy making bows!   I have used silk/epoxy backings in 14 bow attempts (5 failed due to serious tillering errors or serious grain violations.).  If you get undyed silk noil, it actually dries almost transparent, which is kind of cool.  I have used it as backing on Ipe and oak with good results.

I think I have hit the end of the road with my research with silk backings in bowmaking, as the actual process Hickman used seems to have been lost and most bowyers seem to have no idea as to what type of silk they are using.  Ties and blouses seem to be made of very thin silk cloth, which would stretch heavily, particularly if cut improperly relative to the warp (stretched longitudinal) fibers in the weave of the fabric. Most bowyers also seem to use wood glue with silk instead of epoxy which would not help augment silk as most wood glues do not fill gaps well, whereas epoxy generally does fill gaps.    I have done some additional searching (Google "silk epoxy studies") and I have found several recent articles suggesting that silk/epoxy matrix formulations significantly enhance the properties of silk, making it somehat like F-word-Glass (wont say the word - not allowed here).  One interesting article is here: www.academia.edu/7714376/Can_silk_become_an_effective_reinforcing_fibre_A_property_comparison_with_flax_and_glass_reinforced_composites 

I would like to try the same process with high quality flax linen, but I have not found any that I trust locally yet.

If anyone else has any thoughts on my findings, please feel free to share.  We are all here to learn new things.

Good luck and happy bowyering!

SB   

[TimothyR]

Sorry to sneak in on this. But what about silk rovings. I got some to try for bow strings.  Can it be put down like sinew?  Again I'm apologize for high jacking this tread.

[sleek]

I have built three bows with silk backing. One was for cosmetic reasons only ( with the right finish you can make silk mirror finish ) and the only one that didnt break is the one that didnt need it to start. I only used one layer, perhaps more were needed but if thats the case, screw it, ill build another bow.

[PatM]

Jayman,

I am relatively new to bowmaking (2013), however I was drawn in to silk backing as a result of the mention of Hickman using it back in the 1930's in TBB1.  I then recieved a number of bolts of silk noil fabric (woven, unrefined short silk fibers).  It seemed very strong, although it does stretch.  When reading the vague discription in TBB1, it mentions Hickman somehow stretched the silk into tension and then applied the bow to it with some sort of glue.  I did some thinking and developed a rack that I can stretch the silk into tension and lay the bow on.  It requires packing tape as I use G2 epoxy (epoxy does not stick to packing tape, although I still need to pry the bow off the jig with some force).  I did a posting on Trad Gang back in November that shows my basic setup and some of the early results.  http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=012213;p=1#000005  In that thread, it shows a backing strip that actually pulled into reflex after it came off the jig with the silk.  This leads me to believe that silk CAN provide more than just "some protection" to a back if it is applied correctly and a good fabric is used.  I really need to do further research but I am too busy making bows!   I have used silk/epoxy backings in 14 bow attempts (5 failed due to serious tillering errors or serious grain violations.).  If you get undyed silk noil, it actually dries almost transparent, which is kind of cool.  I have used it as backing on Ipe and oak with good results.

I think I have hit the end of the road with my research with silk backings in bowmaking, as the actual process Hickman used seems to have been lost and most bowyers seem to have no idea as to what type of silk they are using.  Ties and blouses seem to be made of very thin silk cloth, which would stretch heavily, particularly if cut improperly relative to the warp (stretched longitudinal) fibers in the weave of the fabric. Most bowyers also seem to use wood glue with silk instead of epoxy which would not help augment silk as most wood glues do not fill gaps well, whereas epoxy generally does fill gaps.    I have done some additional searching (Google "silk epoxy studies") and I have found several recent articles suggesting that silk/epoxy matrix formulations significantly enhance the properties of silk, making it somehat like F-word-Glass (wont say the word - not allowed here).  One interesting article is here: www.academia.edu/7714376/Can_silk_become_an_effective_reinforcing_fibre_A_property_comparison_with_flax_and_glass_reinforced_composites 

I would like to try the same process with high quality flax linen, but I have not found any that I trust locally yet.

If anyone else has any thoughts on my findings, please feel free to share.  We are all here to learn new things.

Good luck and happy bowyering!

SB

  The method used had been described in a  Popular Mechanics article which has been linked to several times. Sadly it is ignored repeatedly and Baker's dogma persists.

[vinemaplebows]

Adding two layers of linen will work against any performance you might acquire because of the added physical weight.  Trying to depend on a crutch to improve your bow building is the wrong path to take. IMO  Concentrating on building the best bow you can with the best wood you can get is your best option to achieve the bow you want.
 I'm not scolding you or picking on you. What I'm trying to do is help you build a bow you will be proud of. It took me over 10 years to get to that point. If I can help you get there without all the trial and error, I've done my will.

I won't say I totally disagree, but then you would limit yourself to board bows with that opinion. Any bow that is Character of any sort, infact I would go so far as to say if the back is not totally flat, you will loose preformance due to excessive added weight. If backing a bow with material is such a drag on the bow preforming, the same would be true for almost selfbow. The crutch is the inability of NOT picking perfect staves, and that my friend is not doable for most people.