Techniglue Dry Time?

[Moss]

Okay I am currently working on my first recurve. I am using technique epoxy and was wandering if you guys know what the general dry time without a heat box is before you start work on the bow shaping limbs etc... It has been drying at 20 degrees Celsius for the last 24 hours and I'm very keen on starting work on it but still want to give it the highest chance of survival

[longbow steve]

Give it another day Moss, How is the glue in your bowl ? Still tacky to touch on the outside ?
Be patient, if you have access to a car and sunlight chuck the layup in if possible. Steve

[Moss]

I'm in Tassie so the car does not heat up much atm. Looks like another day of thinking of something to do. to answer your questin about the glue it is still a tad bit tacky arounf the outside of the container

Thanks for your reply
Moss

[Alex]

Moss, I use a small home heater.
I put the form on top of two buckets, cover with a black plastic and chuck the heater inside, leave for 3 hours, turn off the heater and go do something else.
If I do this in the morning by 9:00 am I turn it off by 12:00 and then go out with the family. I would check in the evening. Go sleep and next morning take the bow of the form and start cleaning up the bow blank.
Good luck.
PICS mate, PICS.
Alex.

[Glenn]

Moss I had a mate who use to make laminated bows and wrapped the form in an electric blanket for around 6 hours, it worked well. The car and the heater are very good ideas.
I will clean my bows up the next day but I leave them for a few day before I brace the bows and start drawing the limbs, but everybody is different...Glenn...

[Steven J]

I would give it a couple of days. There are still a number of jobs to be done before you start stressing the limbs which is where you need to be cautious with uncured glue. Marking out and cutting the limbs is an evenings work with hand tools. Get that done tommorow night and then after that go for it. Best of luck. I am sure that I speak for everyone when I say that I am looking forward to the photos.

Steve

[Moss]

OK....
i have had some problems.... me being the very curious inquisitive and unpatient person that I am. I was starring at the bow and having a bit of a peak at it by moving the inner tube a tad(i know i'm a bad person ) anyway i notice there was a very distinct ridge in my bow after further great difficulty i realized that the fiberglass on the belly had cracked on one side. So i very quickly consulted with my dad and we came to the conclusion that it would be best to inspect the fiberglass and see if we could do anything about it( it had been about 25 hours at 20 degrees so according to the glue it should be fine as long as there is no stress on the limbs. the crack in the glass appeared to go about half way up one limb and do the same on the other though to a lesser extent.

Firstly we decided seems as this is my second attempt at building a recurve i should continue and just see how it goes. So i started to do a bit more shaping around the handle area. after about three hours of me working away at the handle I'd come to the conclusion that this bow would be near to impossible to tiller as the crack had made the glass rise in that area by about 4mm. so i took the bow inside quite disappointingly. Luckily dad had been thinking about it and come to the conclusion the we could remove the fiberglass on the belly with damaging the bow the key is heat. Techniglue has a HDT (heat deformation temperature) of about 60 degrees i believe so this means if you can get the fiberglass to around that temperature you should theoretically be able to remove the broken fiberglass lamination so carefully with a hot air gun and a paint scraper we managed to get the belly fiberglass lamination of without damaging the rest of the bow at all and guess what it worked an absolute charm the fiberglass lamination came absolutely clean off. The belly has gone a bit concave for some reason so I'll have to fix that up tomorrow carefully with sandpaper.

My theory is that as long as i keep the core thickness the same it shouldn't matter to much about what it's made out of.

I'll post some pictures up tomorrow morning if i get around to it... I'll be more annoyed than usual if this bow brakes at least if it survives it'll have character

[longbow steve]

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Hi Moss, With regard to the crack, were you using tiered cauls to accept the pressure of the rubber bands? Check also that your form is as wide as your laminations.
I dont know that sanding the peak of the core is going to do you much good as the edges will be thicker however you may end up with an ACS (Adcock cross section) and have a real performer on your hands .

[Moss]

okay just some picture about whats happened and in answer to your post Steve i have not been using cauls though shall make some today and the sand shouldn't make the edges thicker as only the belly is rounded 5the back of the bow was in direct contact with the form so it is dead flat.

sorry about some of the blurry pictures

[longbow steve]

Hi Moss, You do need the cuals to prevent the cracking. StevenJ suggested using 3mm MDF a while back, I just uses 3-4 mm bamboo strip as it is available.
You will end up with somthing and will have learnt alot so keep going. Steve

[Moss]

so when making cuals do you just make 3 or so exactly the same width as the form and bow ord do you make them so they taper in a pyramid like fashion

[longbow steve]

I make one the same width as the layup, and another 10mm less and this seems adequate but you can put another on 10mm or so less again.
Make sure they can bend without resistance around the curves otherwise you will be fighting against them when laying up.
Steve