Main Discussion Area => Bows => Topic started by: Minuteman on April 12, 2007, 06:52:04 pm
Title: Lam. bows/ what kinda clamps??
Post by: Minuteman on April 12, 2007, 06:52:04 pm
Alright I orderd some spring clamps 4", too small ,sendin' em back. What kinda clamps do you folks use when making a laminated bow? Just watched Dean torges' video on the BBO and I can't see buying that many big C clamps. Got any ideas for me? Will a larger 6" spring clamp work? Pics are good too.
Title: Re: Lam. bows/ what kinda clamps??
Post by: ridge on April 12, 2007, 07:12:30 pm
MM I use a two piece form with the air hose. I know guys who use the rubber band forms with good results. Seems to me but i could be wrong that the money spent for all those clamps would buy the hose and plywood for the form. I got my stuff years ago from Bingham Projects. I imagine that you would have to take care to not overtighten the clamps which might cause glue starvation or to little which may cause a bad glue line. We all have the combo that works for us. Ridge
Title: Re: Lam. bows/ what kinda clamps??
Post by: huntersim on April 12, 2007, 07:19:00 pm
Chris,
I have about 10 6" c-clamps that I use near the riser, and then I use some 2 1/2" c-clamps for the rest of the way out. The little ones seem to work OK if you use a good pressure strip and dont over tighten them. If you over tighten them and dont use a good pad, you'll leave "dents" on the bamboo. You dont want that. :) If you use a floating form like D. Torges shows you can also use the clamps like Justin uses, with wood blocks and rubberbands.
Title: Re: Lam. bows/ what kinda clamps??
Post by: venisonburger on April 12, 2007, 08:06:53 pm
Don't know what kind of bows you're building, I do tri lams with bamboo and use the jig shown below, it's made by drilling 5/16" hole as far apart as you want and pounding in pcs of arrows that were cut off on the saw to the same length, I use a bicycle inner tube cut into rings and stretched from one peg, over the lams to the peg on the opposite side, my glue lines turn out good. I use URAC 185. the other method is, I have long pcs of rubber that are 1 1/2" wide, bike innertubes split in half work, I clamp one end and wrap tightly at an angle to the other end and clamp, you can get pretty good pressure this way. VB (http://i105.photobucket.com/albums/m229/mostrenga/boobowpics011.jpg)
Title: Re: Lam. bows/ what kinda clamps??
Post by: Justin Snyder on April 12, 2007, 08:39:23 pm
I like that form VB. You been holding out on us, I haven't seen that one before. ;D Justin
Title: Re: Lam. bows/ what kinda clamps??
Post by: D. Tiller on April 12, 2007, 09:10:58 pm
Say do you have a picture of the bows that come off that jig? I'm trying to figure out by looking at the jig and picturing it in my mind but I have no idea which way its bending!
David T.
Title: Re: Lam. bows/ what kinda clamps??
Post by: venisonburger on April 12, 2007, 10:51:36 pm
This form was one that I made when I first started making boo bows, not thinking I made the form as the negative of what I wanted. what I end up doing with this form is doing my belly and core layers and then after dry I attach my back of raw boo and use the long rubber material to wrap it. For anyone who doesn't understand the problem with this form, if I tried to do all three lams at once, I would have the raw boo down first, with the radius of the boo it would rock left or right and I wouldn't be able to keep the lams from sliding apart. So basically If I were to do it again, I would use the part I cut out from the board and throw this pc away.These are some that came off the form, It works and I don't want to waste it. (http://i105.photobucket.com/albums/m229/mostrenga/VBTR6.jpg) (http://i105.photobucket.com/albums/m229/mostrenga/VBTR1.jpg) (http://i105.photobucket.com/albums/m229/mostrenga/Picture031.jpg)
Title: Re: Lam. bows/ what kinda clamps??
Post by: Minuteman on April 13, 2007, 08:25:47 am
I've been doing Hik backed bows so using a form like you showed is kinda what I've been doing. Putting the backing down against the jig and using rubber strips wound across cut off arrows stuck through it. I'm quickly running out of hikree though so I'm gonna start into my bamboo pile soon. Guess I'll try the rubber bands and little sticks thing on my next one, see how that works out.
Title: Re: Lam. bows/ what kinda clamps??
Post by: ridge on April 13, 2007, 09:34:57 am
V Burger, I use a piece of felt carpet underlayment on the form so that the raw boo nodes sink into the felt. I first used it on the boo bows but now even use it on my forms for G bows. My glue lines come out great.
Title: Re: Lam. bows/ what kinda clamps??
Post by: DCM on April 13, 2007, 10:04:40 am
You can use the pedistal type from and rubber bands. Just wrap the whole clue up with bands and clamp it down onto the supports. If it's hot summer you gotta move along pretty good. And it's messy as the dickins. But it works. I pick up truck inner tubes, or ag, from a tire shop dumpster in town. Any big truck/ag tire store will have old tubes for give away usually. can bands of 1" to 1 1/2" out with scissors. I used the air hose setup for a glass build. Won't go that route again. Gonna do on like Venisonburger for my next glass project. Not sure how good that works for boo backed, seems like the nodes would mess you up.
Title: Re: Lam. bows/ what kinda clamps??
Post by: StanM on April 13, 2007, 10:38:38 am
Mornin' David,
How have you been?
You gotta build it in the inverse. If you do that then the boo side is up and you don't have to worry about it sliding. I built one that way and it works fine.
Stan
Title: Re: Lam. bows/ what kinda clamps??
Post by: Justin Snyder on April 13, 2007, 11:07:57 am
Like Matt said, I just use rubber bands and little blocks I made. Here is a link to the thread explaining mine. http://www.primitivearcher.com/smf/index.php/topic,1978.0.html Also if you cut a form like Matt's and use the other side of the cut like he says, you could just use the rubber bands to loop from pegs on one side to pegs the other. The only problem with that is a riser could get in the way. Justin
Title: Re: Lam. bows/ what kinda clamps??
Post by: DCM on April 13, 2007, 02:57:56 pm
Real fine Stan, and you?
Ah, work upside down. Same as a pedestal form. Then you mate up the riser wood after I assume.
Funny story, I spent half the day perfecting the wrong side of my first glass form on the drum sander. Duh.
Title: Re: Lam. bows/ what kinda clamps??
Post by: markinengland on April 13, 2007, 06:02:37 pm
I double wrap the glued up bow in a car inner tube "bandage" then use just a ferw clamps and wooden blocks to give the reflex or deflex wanted. Works well with a long open time glue like resorcinol. Gives a good glue joint, and doesn't slip like clamps can. Mark in England
Title: Re: Lam. bows/ what kinda clamps??
Post by: StanM on April 13, 2007, 08:14:07 pm
David,
Yep, you got it. Riser wood goes on last when done like this. I've been good. Way too busy, but good.
Stan
Title: Re: Lam. bows/ what kinda clamps??
Post by: Gordon on April 13, 2007, 11:22:46 pm
I used a combination of 4" spring clamps and c-clamps to setup my last bow. I was pretty happy with the result. I'm surprised that the spring clamps are not big enough for you - how thick are the limbs?
Title: Re: Lam. bows/ what kinda clamps??
Post by: Minuteman on April 14, 2007, 10:09:57 am
The 4" clamps looked like they would have worked ok on boo but on a flat hik backing it just didn't look like they would hold things flat to the edge. I could have cut little blocks to spread out the pressure but there was only 7/8" of jaw opening to work in. That doesn't leave alotta room to put in a block, so I sent them back.I think a 6" clamp woulda worked fine, wider jaws and more jaw opening for pressure blocks. I'm gonna try out Justin's rubber band method soon. Gonna build a Torges style post-form today.
Title: Re: Lam. bows/ what kinda clamps??
Post by: Pat B on April 14, 2007, 10:26:24 am
I have noticed on hickory backings that the edges curl up when water based glue is used. Thats where I have problems. A good pressure strip helps. I use a piece of sheet metal for this. I like spring clamps better than screw clamps. I have had screw clamps loosen up in the hot box, I guess as the moisture of the glue exaporates and the wood components shrink. Spring clamps keep pressure on the work even if the glue up shrinks a bit. I have never been able to get good glue lines. I may start trying rubber bands or inner tube bands and see how that works for me. I usually don't do many lam bows but I know I will make a few in the future. Pat
Title: Re: Lam. bows/ what kinda clamps??
Post by: venisonburger on April 14, 2007, 09:55:55 pm
I like the idea of the carpet felt I'm gonna try that, I forgot, I buy a roll of plastic wrap, and cut it in half with a razor knife so it's only half as wide, then I roll it along the top of the form, then place my lams on top then bring the plastic wrap over on each side so the glue is contained inside before I rubber band it. I also use some cheap spring clamps in the center since you have to pull it down so far. VB
Title: Re: Lam. bows/ what kinda clamps??
Post by: episaacs on April 14, 2007, 10:12:20 pm
I use foam rubber cut into sections to fit between the boo nodes, between the backing and the form.
Title: Re: Lam. bows/ what kinda clamps??
Post by: OldBow on April 15, 2007, 02:25:34 pm
In the current issue of PA Vol 15 Issue 2, pp. 48-51 is an excellent article by Jim Boswell "A Reflex Deflex Glue Up". He uses U-bolt clamps.
This is an excellent thread. Thanks for sharing.
Title: Re: Lam. bows/ what kinda clamps??
Post by: Hillbilly on April 15, 2007, 03:09:41 pm
In Jim's article, looks like he's only clamping it at the handle and midlimbs, the rest is wrapped together in Saran wrap?
Title: Re: Lam. bows/ what kinda clamps??
Post by: Minuteman on April 15, 2007, 07:19:44 pm
Hey , Justin,do you think theres enough time to get the whole thing rubber banded together when using titebond 3? How long does it take you normally to get one rubber banded together?