Mold under skins

[osage outlaw]

You said they formed where the glue was thicker.  Did you leave globs glue under the skin?  You need to squeeze the excess glue out.

[bradsmith2010]

I did have some mold on some hide glue I left out,, maybe your glue cured slow enough in the high humidity to make the spots,,
I think next time put the bow by a fan or something to speed dry time,,,

[Dakota Kid]

If you wipe the bow with alcohol or acetone before your next glue up it should sterilize the surface. You could have spores in your glue, but more than likely with just a couple spots it came from the air. Putting your bow in a bright place while drying will also help.

I don't know if ammonia will make the color disappear but a bleach water mix will. I use the same thing on moldy basement walls prior to sealing and algae covered decks before refinishing.  I mix 50/50, but you should probably do less bleach, maybe 70/30.

[Pat B]

I wash skins, sinew and rawhide(and the bow) with Dawn soap and warm water to remove any grease or oil from it before gluing it down.

[Dakota Kid]

I often use soapy water too. It's my most reached for squirt bottles. I usually follow with denatured alcohol. It gets anything the soap may have missed plus helps the remaining water to evaporate faster. Getting rid of the water is only really necessary when using oil/poly based finishes.

[Sasquatch]

Yup. Smear glue on the night before so it dries hard and smooth. Then add more glue and a skin the next day.

Thanks for this I didn't know the night before thing. 

[missilemaster]

I have also had that happen with sinew. I think what happens is that the glue dries/cures before the skin dries completely, not giving the moisture anywhere to go. make sure your skins are pliable but not dripping when you put the glue on. I soak them for 10 minutes or so then squeeze them out with a towel. But think about this, because copperhead skins are thinner, you may just be able to see the mold easier. for all I know, the same thing could be happening under other skins, but you cant see it because they are darker or thicker.

[PatM]

Getting your materials as sterile as possible and putting in a cold dry area initially is the best bet for reducing mold growth.
 I would think that this was the reason old time composite bows had a particular season for each process.
 If you sinew in the colder dry months you'll have better luck.

[BowEd]

Sure hope it works out ok for ya.I think it will.Got a feeling there was a combination of things going on for this to happen,but I agree the winter is the best time for these things.

[Eric Krewson]

I am not an advocate of wrapping skins when you put them on because you are only putting pressure on the sides unless you have a high crown bow.

If you roll your thumbs to the outside of a limb over and over for about 15 minutes you will  get all the excess glue and air bubbles out. I start at the handle and work my way side to side to the tip then start over again. You don't have to worry about your skin coming off after about 20 minutes. You can tell when it stops moving under thumb pressure.

Like this;

[Dakota Kid]

If all of your soaking and pre-moistening of skins/sinew is done with 50% rubbing alcohol you'll never get mold. I use it when I water down my glue as well.

[PatM]

A small wallpaper roller works very well for smoothing the skin/glue bond and squeezing out excess.  Basically designed for the same purpose. Couple of bucks at HD or the like.

[mullet]

Vinegar works better then ammonia or bleach. I have sealed TB airtight with skins before and the glue did not fully dry.