Sizing with hide glue...

[RatherBinTheWoods]

Just a quickie. I am just about to have a crack at my first sinew backed bow - a nice little elm, Kiowa style, bow - that started out as tinkering but ended up quite interesting with some nice wavey character and an thin elegant profile. Not a great piece of wood though so to give it some longevity ( and a few more #) I thought I try the sinew treatment.

I have the sinew processed and the powdered hide glue ready to go in the double
boiler but my question is can I size the bow well ahead of doing the actual application or is it best to size, leave a shot time (couple of hours)  and add the sinew while it's still tacky?

Essentially I'm asking could I size this evening and then complete the backing  at the weekend without any issue?

Cheers

[Pappy]

I always let it dry overnight, just a very thin coat. Several on here that do it a lot more than me, maybe they will chime in also, but that is how I do it.
 Pappy

[RatherBinTheWoods]

Thanks Pappy, it may turn out that its one of those things that's not crucial but as I spent so long processing the sinew, thought I'd check rather than have it pop off on the first shot :0)

[PatM]

Just paint a layer down and go right to sinewing. No need to leave it at all. Once a sizing coat is down it's not going anywhere.

 

[BowEd]

Thanks Pappy, it may turn out that its one of those things that's not crucial but as I spent so long processing the sinew, thought I'd check rather than have it pop off on the first shot :0)

In fact it's one of the more crucial things to be done for a good bond before sinewing but is'nt hard to do at all.The first sizing soaks in.Let dry a couple of hours.Second lays on top of that left to dry and then the third until it looks shiny.Sanding with fine paper in between.Using a thinner consistency in the beginning helps to get it into the pores of the wood good and proper.
Then it's ready to be sinewed any time.Even a day later.I would'nt wait a week though.Oxidation can happen.Just lightly sand it to be sure oil from fingers or a foriegn source is'nt on there and apply a good coat on before putting your hide soaked sinew on that's all.Have fun.Sinew is some amazing stuff.

[PatM]

I've never had sinew budge after just painting one layer and moving ahead. The first coat gels in minutes and at that point the next isn't going to migrate through it. Nor is a dry layer of glue as good as a wet layer for initial bonding.

[BowEd]

That's good Pat.I'm glad your shooting them.Each to his own.All I know is Pat that a person better get the sinew bonding to the glue layer on top of the wood that is wet with the pores completely filled below.You want the sinew to bond to the sizing not the wood alone.A shiny layer on top of the wood after the wood has been roughened up.Bottom line.
The thing to avoid here is a dry joint bond,and am glad you have never had it occur to you.

[Stick Bender]

I dont know maybe Im overly cautious but the last sinew bow I did I put 4 sizing coats on over a week & the last one the night before sinew & used acid tone , soap & water prior to sizing I think its wiser to take the more cautious path just my 2 cents.

[Pat B]

Like PatM I only size just before adding the sinew. I do wash the bow with Dawn dish soap and rinse with boiling water. This moistens the wood and preps the dry wood to accept the hide glue.

[DC]

Isn't one of the advantages of hide glue that the new layer re-activates the old layers? If that's the case then it wouldn't matter if the sizing dried or not.

[PatM]

I've even sanded a back with 220 and just laid sinew down without sizing at all as a test. It really seems to make no difference. You can try just laying a few strands on unprepped wood and try pulling them off in a few weeks. It will always fail within the sinew itself.

 Most failed sinew bonds are due to contamination than actual glue failure.

[Pat B]

 like doing it all at once to be sure no finger prints or other contaminants can get on the glue surface. If I
m adding a few layers I wrap the sinewed limbs with gauze or strips of old bed sheets to help smooth the sinew but also to protect the surface. The cloth strips breath so they don't impede the moisture loss.

[Marc St Louis]

I only apply one coat of sizing and apply the sinew within the hour.  I do sand the back first with medium grit paper.  I also apply all the sinew in one shot, usually

[BowEd]

That's right DC.
Contamination is easily avoided without much effort if done in stages with larger amounts of sinew being applied.
As I said each to his own.

[mikekeswick]

Just paint a layer down and go right to sinewing. No need to leave it at all. Once a sizing coat is down it's not going anywhere.

You wouldn't want it to be in its gelled state when you want the backing added. The fresh sinew would likely reactivate the gelled glue but.....much better to add a couple of coats of thinner 5 - 10% glue and let it dry (will only take an hour or so). Do not size with the same consistency of glue as you use for the sinew. 25 - 30% glue for the actual sinew. It is also useful to warm the back of the bow well before sizing to increase the penetration.