Air Bubbles in Linen Backing

[BassBow]

I am wondering what air bubbles look like after the linen has been applied to backing. I am backing a bow with linen and there are imperfections. It isn't smooth. I ran my finger over the back many times to make sure there were no air bubbles. I just can't find any pictures on line to show me what the backing should look like. Thanks!

[Jomohr84]

Howdy BassBow,

I have applied canvas backing on my first bows, so I believe linen should be similar. I iron the strip to get it nice and smooth. I learned to cut it a little longer than the bow, as it seems to shrink. Then I soak it in a large bowl of water while I size the bow's back with TB3. Once the glue is tacky, I pour on another fairly thick layer of glue.

Now the important part. Take the linen out of the water and be careful not to crease it, or it will result in a lumpy back, and won't end up smooth. To get most of the water out, I lay it on a towel and pat it with another towel so it ends up just damp, not soaking wet.

Then I start at one limb tip and smooth the cloth on as I lay it down, going the entire length of the bow. Once it is smoothed on and straight, pour on a generous amount of glue and smooth it into the cloth, until it is saturated. Then wipe off any excess glue with your finger. I pull the cloth down a bit around the edges periodically as the glue sets, since the cloth likes to curl and lift a little, but once the glue is set, its good to go. I wait 24hrs, then trim with a razor utility knife. I have had good results with this method, but when I just squeezed the water out of the cloth instead of patting it and not creasing it, it turned out a bow with crease marks and little lumps on the back. It still worked fine as a backing, but was less attractive.  If I have time tonight i'll post a pic of the difference between the bows I did.

[BassBow]

Here is a pic of the backing...my apologies.
   
Any method to fix the lumpiness? Oh well. Newbie mistake.

[Jomohr84]

Hmm yeah it got pretty lumpy. Not sure what could be done to remedy that,  I guess i'd saturate it with glue again and smooth it as much as possible if the lumps soften up a bit. I think then it  would be as good as you can get it, may not look the best, but will work as a backing. Just have to try get it better on the next one. It looks to me like the linen and wood may have sucked up some of your glue.  I make sure to size the bow back real good, so the wood doesn't suck up the glue from the linen, then saturate the linen real good after applying it, so the the end result is smooth with no dry spots.

[BassBow]

Jonathan,

Thanks! I will take your advice the next time around. I just saturated the bow with glue over the lumpy linen. It looks like it will do the job. At least it will look better. Thanks! I'll try to get some pics up when it dries.

[Eric Krewson]

Looks like excess glue to me.

I haven't backed a bow with linen but I have put on dozens of snake skins.
 
I remove excess glue by rolling my thumbs from the center of the skin to the outside edge. I do this at least a dozen times up and down the skin during the first 15 minutes after I apply the skin.

 

[Stiks-n-Strings]

I'm in the same boat as Eric, never used cloth. I do my skins the same way Eric does with great results.

 If I was gonna do a cloth backing I would do it like was reccomended and work out the excess glue like Eric reccommended.

[Jomohr84]

Not trying to rock the boat, but I still feel more glue was the answer, or perhaps sizing the back prior to glue up. From my experience with canvas, the light/white areas are dry and did not adhere well due to glue being absorbed by wood and surrounding linen, compared to the darker areas, which got enough glue. The lumps would be excessive glue, but I believe with a good sizing, then adequate saturation and smoothing off of excess glue, it would turn out better.

[briarjumper12]

Eric, Good idea on putting tape on the side of the limbs when putting the skins on.  I put my skins on the same way as you and will put tape on the side next time. Will save some clean up for sure.

[razorback]

Bassbow, if you are still looking to fix this bow you could heat the back until the glue softens, to release the backing and then proceed as directed above.

[Eric Krewson]

John, I cover the belly, sides and handle of a bow with painter's tape before I apply skins. Sure makes clean-up a breeze. You can't tell it from the picture but the tape is about 1/16" lower on the sides than the back of the bow, the tape doesn't interfere with the skins when they are applied.

 

One time, before I masked off my bows, I thought I had sanded off all the excess glue from the limbs after applying skins and proceeded with the finish. A couple coats in I could see some little light colored islands here and there on the limbs, dang, excess glue I had missed.

After stripping the bow and starting over I decided to mask them off in the future. Takes about 10 minutes to mask one off but pays off big in the long run.