Bowclamp?

[Greg Urwiller]

Anyone have/used the "Bowclamp" setup? I've used a caul setup before, but never had one with a "bow" in it like this. Greg

[Chris Fournier]

Years ago I made several "bowclamps" as I imagine that you're referring to. In my opinion the only reason to make or use one would be to compensate for a lack of clamps while gluing edging. If you lack enough clamps for a large job then they're worth making up. I haven't used my bowed clamps in years but haven't disposed of them because, well, I made them and that took effort. They are effective dust collectors and conversation starters.

[Van Huskey]

I assume you are talking about the commercial product. If so they are great, they do exactly what they say they will do. If you have or have access to a CNC machine you can make your own.

[Mike Henderson]

You can make your own bowed cauls without a CNC machine. See here (http://www.mikes-woodwork.com/Cauls.htm).

Mike

[Cost is just a few dollars - but you provide the labor. So if you have more time than money, make your own.]

[frank shic]

haven't used my set in ages...

[Chris Padilla]

Love 'em...come in very handy. They aren't only for situations arising from a lack of clamps but can be used to clamp situations where it is impossible to fit a clamp and one can only reach the ends of the caul.

[Mike Cutler]

Yep

I just used them recently to do a large, 7/8" thick curved panel lamination. I had male and female forms and used the Bowclamps to bring everything together. No way to get a clamp into the middle of those forms.
I also just used one, in concert with a hydraulic floor jack, to jack up one side of my Mini Cooper, then the other side, to rotate tires and do a brake job, but I don't think that's an advertised use of a Bowclamp.:cool:

[Chris Padilla]

That use for jacking up a car requires a pic, Mike! Next time! :)

[Chris Fournier]

Hadn't given pause to think about using them on panel work as others have. I needed them for edge gluing a large number of panel and clamps/time were my concerns. I guess I missed the forest for the trees on this one. When I have needed a bowed caul to apply pressure where my clamps won't reach, I've sanded the bow profile on my edge sander starting at mild and then trying the caul under pressure to make sure that the bow is approriate for the pressure. I continue to add more bow until I get the clamping action that I need. I pretty much consider cauls for this application to be one use unless it's a small production item that I am making.

[Dave Houseal]

I've seen the bow-clamps at a show once, and thought they looked very nice. I actually almost bought a set, but I couldn't bring myself to spend the money. Since then I've made a couple cauls after seeing Mike Henderson's tutorial posted above.

They turned out great, only took maybe 10 minutes to make a set. I even made mine out of some scrap oak that had been lying around the shop.

They aren't as pretty as the bow clamps, and I don't have the nice little track for my f-clamps to slide in, but the price was right.

[Scott Schwake]

You can make your own bowed cauls without a CNC machine. See here (http://www.mikes-woodwork.com/Cauls.htm).

Mike, in the first picture that looks like an I-beam type caul, how did you make that one? Great tutorial, thanks.

Scott

[Tri Hoang]

They are simple to make and effective...I made them after seeing Mike's excellent tutorial.

[Mike Cutler]

"That use for jacking up a car requires a pic, Mike! Next time! "

It might have to wait a few months 'til I put the summer wheels back on.
You can jack up one side of a mini with just the front jacking point, but to get it safely onto jackstands, for the brake job, it had to all come up at once evenly. A 36" Bowclamp does a nice job.
I was going to email Craig a pic, but I got immersed in the work I was doing.

[Chris Padilla]

He'd love the pic for sure!

[Aaron Beaver]

I have a set of the Bowclamps and use them on almost every project. Mostly I got them because getting Bowclamps was cheaper than buying a bunch of clamps that I didn't have right then. My thought was I could build up my clamp collection over time but use the Bowclamps in place of all the clamps I didn't have. Still use them because I haven't needed to buy a lot more clamps since I have them, I have bought a few clamps just not as many as I thought I would of by now.

On a side note: There is only one thing I didn't like about the Bowclamps and that was releasing them. There is a lot of pressure built up in them and when you loosen one end the other end and clamp could let loose.....then there is this big "spring" effect that scared the heck out of me the first time it happened. Just takes a system to get the clamps off so doesn't jump around, just have to release a little pressure on each end a little at a time.

Also.. clamping them down with parallel clamps is not that easy, can be done but I haven't found an easy way yet. Reason being is the clamp you do first will become loose when you tighten the other end, well if you don't have any threads left for tightening then you have to try and slide the jaw but the bowclamp has pressure on it so you can't just let the parallel clamp loose or the bowclamp will spring out. My solution so far is to use a third clamp and use it on the first end to re-tighten that end down and then just take off the one that was there.

Just some thoughts on what I have noticed using them, I do like them, just took some getting used to, maybe others on here have some tips.

[Scott Vigder]

I've had my Bowclamps for several years and use them frequently. They are worth every penny.

[Chris Padilla]

Aaron,

That is pretty much what I do with the bowclamps: use a 3rd clamp if/when necessary and loosen both clamps at the same time or a little bit at a time to prevent soiled undies. :) They are a tool like anything else and one needs to learn how to use it.

[Mike Henderson]

Mike, in the first picture that looks like an I-beam type caul, how did you make that one? Great tutorial, thanks.

Scott
If I recall, I used some 3/4" MDF for the flanges and 1/4" MDF for the web. I cut a groove in the 3/4" stock to let in the 1/4" web so that it would be glued in well. One thing to watch for is that when you cut the groove (if you use your table saw) is that you keep pressure on the stock so that the groove is equal depth all the way. Otherwise, when you go to glue up, you'll have a bow in the caul. If you want a bow, I'd put it in the 1/4" stock before glue up.

You could also use your router to cut the groove.

For what I was doing, I wanted a flat caul, not one with a bow, so that's what I made. Making an I-beam caul is pretty simple. The I-beam structure is good for long cauls.

Mike

[Jim Becker]

Yes I have several sets of Bowclamps and they work as advertised.

[Paul Johnstone]

I made some homemade cauls. I think they are great for clamping the face frame to a plywood carcass. Fewer clamps are needed, and the pressure is spread evenly.

I put one Bessey clamp in the middle of the cauls (at 90 degress) to hold them in place. Then I use Besseys on each end to tighten them down. After all the clamps are in place, I will sometimes add a couple more Besseys on the cauls. Not because it's necessary, but it makes me feel good.

[Greg Urwiller]

Thanks to everyone for the replies! The reason I was asking about these, is that I'd like to laminate a bench top, and these look like they'd be better than clamping the whole length of the top with clamps. That would take a lot of clamps! I'm in no hurry, so I could make my own. We'll see. Thanks again. Greg

[Adam Augustine]

You can make your own bowed cauls without a CNC machine. See here (http://www.mikes-woodwork.com/Cauls.htm).

Mike

[Cost is just a few dollars - but you provide the labor. So if you have more time than money, make your own.]

Mike, I just wanted to say thanks for your post about the bow clamps. The pictures from your web site were very helpful. Adam

[Jerry Thompson]

I made the ones shown by Mike Henderson. They work as advertised and I find them a great time saver in panel glue ups.

[Clay Fails]

I purchased a few sets at a show a couple years ago. I think they work very well, exactly as advertised. They are pricey, and I'm sure you could probably make something similar on your own. if you have the budget and don't want to mess with making your own, they are nice to have.

[Michael Kellough]

I purchased a few sets at a show a couple years ago. I think they work very well, exactly as advertised. They are pricey, and I'm sure you could probably make something similar on your own. if you have the budget and don't want to mess with making your own, they are nice to have.

If nearly as good is good enough...

[Biff Phillips]

I Also.. clamping them down with parallel clamps is not that easy, can be done but I haven't found an easy way yet. Reason being is the clamp you do first will become loose when you tighten the other end, well if you don't have any threads left for tightening then you have to try and slide the jaw but the bowclamp has pressure on it so you can't just let the parallel clamp loose or the bowclamp will spring out. My solution so far is to use a third clamp and use it on the first end to re-tighten that end down and then just take off the one that was there.
.


This is a good idea. I often will put a clamp in the middle of the caul to help hold it in place while the ends are being clamped.
I use my homemade cauls for gluing faceframes to plywood carcasses. They really work well for me in that application.

[Stew Hagerty]

I actually have two sets of each size of the one-time-tools cauls from Woodpeckers. They're made from glue proof Phenolic material. I use them almost any time I need to glue up a panel.

http://www.woodpeck.com/ottclampingcauls.html

[Tipton Lum]

This is how I make them.
Make Your Own Curved Clamping Cauls (http://www.sawmillcreek.org/showthread.php?209901-Make-Your-Own-Curved-Clamping-Cauls)

[johnny means]

Bowed cauls are also useful for keeping wide panel glue ups flat. Of course, they must be used on a known flat surface.

[Mike Heidrick]

Ron has some for sale on woodnet. They are/were perfect - I sold them to him last year :)