First time build, don't know where to start.

[Susquehannariverarcher]

I picked up a kennym forward handle kit, and feel slightly overwhelmed, ha. I know I just need to start and I'll probably answer my own questions. But thay won't be till archery season is done (obviously). Anyways for a form should I go lvl beam or mdf. And are there any other tips before I get started?

[Smguinnip]

Well, you’re already on the right track, going with a Kennym bow/design and coming on here for advice. I was in your shoes last year and all of these guys are a huge help. Good luck and post pics.

[Susquehannariverarcher]

Appreciate it! Definitely looking forward to the process.

[kennym]

I have one form made from MDF before I started hearing about them breaking while in the heat box under pressure. So I added  some about 8" wide plywood around the bolts and used it some more without breaking, but I finally built a new one because the stress wasn't worth it. LOL

I haven't used the LVL but some guys say it's good.  The stuff I looked at here at my local lumber yard was crooked so I still lam plywood up for the form blank...

[Crooked Stic]

Two pieces of 3/4 and a piece of 3/8s will get you a twig over 1.5 then thickness sand  to thickness.

[derekdiruz]

Regarding the form: I made mine from plywood for the time being. Pending how they hold up, I may try another route.

Aside, I purposely oversized my forms to 1.75” when I use 1.5” stock. I routed in placement for big fender washers that hold everything in place and square. This has a couple purposes for me. One, holds everything in the correct spot. 2) I don’t need to align them manually I can just put them within the washer guides and it’s a relatively snug fit, so I know they’re aligned and won’t slip. 3) the squeeze out stays lateral and coplanar to the laminations- which makes it way way easier to cut off or sand off square when I clean up the slag.

My other tip is dry fit, dry fit, dry fit.

[Susquehannariverarcher]

Regarding the form: I made mine from plywood for the time being. Pending how they hold up, I may try another route.

Aside, I purposely oversized my forms to 1.75” when I use 1.5” stock. I routed in placement for big fender washers that hold everything in place and square. This has a couple purposes for me. One, holds everything in the correct spot. 2) I don’t need to align them manually I can just put them within the washer guides and it’s a relatively snug fit, so I know they’re aligned and won’t slip. 3) the squeeze out stays lateral and coplanar to the laminations- which makes it way way easier to cut off or sand off square when I clean up the slag.

My other tip is dry fit, dry fit, dry fit.

I'm having trouble picturing what you are doing with washers. But it sounds interesting.

[Kirkll]

I would highly recommend going with 1.75" LVL material and keep it full thickness. If you are only using 1.5" lams and glass you can use a router and dado out slots on each side to center it up.  i wouldn't recommend washers at all. i would just use zip ties... drill 5/16" holes below the form edge about an inch down and space them about 8" apart.

Here is an old video of a recurve lay up i did years ago when i was using silicone heat strips. Those worked just fine for awhile, but had no longevity. I since have upgraded to a different heat strip method that i've used for the last 10 years. I thought this might be helpful to get you started.

https://youtu.be/uAMsgze0u7Y?si=bZUCil2Hb-nRO2rM

Personally.... i detest hot boxes... It's really hard on your forms cooking them at a 160 degrees time and time again.  But.... I build a lot of bows,  and prefer the time saved using heat strips, and have no worries of my forms warping like they do after awhile using a hot box....

I can lay up a set of limbs , two separate lay ups , in about two hours time, and have them milled and mounted on the riser the same day if i want. But i typically wait until day 2 to put a string on fresh limbs to make sure the epoxy is fully cured over night.     .02 cents worth.  Kirk

[derekdiruz]

My explanation is sub par for sure, but the big fender washers that I use, are used as lateral guides. If you watch the video that Kirk linked - on his form he has small squares of wood (it appears) that are lateral guides. I used washers instead (as I had them on hand and it was simple).

Kirk, I love that zip tie idea.

[Susquehannariverarcher]

I would highly recommend going with 1.75" LVL material and keep it full thickness. If you are only using 1.5" lams and glass you can use a router and dado out slots on each side to center it up.  i wouldn't recommend washers at all. i would just use zip ties... drill 5/16" holes below the form edge about an inch down and space them about 8" apart.

Here is an old video of a recurve lay up i did years ago when i was using silicone heat strips. Those worked just fine for awhile, but had no longevity. I since have upgraded to a different heat strip method that i've used for the last 10 years. I thought this might be helpful to get you started.

https://youtu.be/uAMsgze0u7Y?si=bZUCil2Hb-nRO2rM

Personally.... i detest hot boxes... It's really hard on your forms cooking them at a 160 degrees time and time again.  But.... I build a lot of bows,  and prefer the time saved using heat strips, and have no worries of my forms warping like they do after awhile using a hot box....

I can lay up a set of limbs , two separate lay ups , in about two hours time, and have them milled and mounted on the riser the same day if i want. But i typically wait until day 2 to put a string on fresh limbs to make sure the epoxy is fully cured over night.     .02 cents worth.  Kirk

Very interesting technique. There is so much I have to learn!

[Kirkll]

There are many different types of forms and systems you can use to build bows. EA 40 epoxy can be cured at room temp without using any heat too. I never cook my riser footings, and have had my heat strips fail in the past and had those limbs come out just fine curing for 24 hours with no heat...

The biggest thing to watch is making sure you build your form with perfect 90 degree angles and zero twist in the form. Nothing worse than starting out a bow with twisted limbs.... After building your form, check it closely for twist, then seal it really well with several coats of shellac, or some kind of good sealer.... If you are going to use a hot box, its very important to check that form for twisting every time you use it. Those hot boxes are tough on laminated forms, and even LVL forms.

Kirk

[Susquehannariverarcher]

There are many different types of forms and systems you can use to build bows. EA 40 epoxy can be cured at room temp without using any heat too. I never cook my riser footings, and have had my heat strips fail in the past and had those limbs come out just fine curing for 24 hours with no heat...

The biggest thing to watch is making sure you build your form with perfect 90 degree angles and zero twist in the form. Nothing worse than starting out a bow with twisted limbs.... After building your form, check it closely for twist, then seal it really well with several coats of shellac, or some kind of good sealer.... If you are going to use a hot box, its very important to check that form for twisting every time you use it. Those hot boxes are tough on laminated forms, and even LVL forms.

Kirk

What's the best way to check for starlightness?

[Crooked Stic]

If you are using a hot box it don't take that much heat mine vary rarely gets much hotter than 130. In the summer I have layer up two limbs on the same form. After about six hours.

[Kirkll]

I’m not sure what you meant by “starlightness” , must of been an auto correct thing on your PC….  But if you are talking about checking a form for twisting, there are a number of ways you can do this. The simplest method would be laying your form on a perfectly flat surface and use a square. Check your flat surface first with a straight edge diagonally from corner to corner.  Some guys just tape carbon arrow shafts on the form and eyeball it….

Unfortunately the forms that I have had twist in the past, I didn’t catch it until I was prepping the limbs for the riser. If you look at these photos you can see how I check the limbs for 90 degrees on a machined surface of the edge sander. It is perfectly square at the butt, the mid limb, and at the hook, there is no twist to your form. This is a perfect way to check your limbs prior to mounting them on a riser, and is critical for recurve limbs.

https://photos.app.goo.gl/KxYM6HaNonvtWqW86

Most bowyers get started with long bows that are more forgiving due to deep core narrow limbs are not so touchy about perfect alignment and tracking issues. You can learn all the other little tricks about tiller, and shaping tip notches and different types of grip shapes…. After you have the basics down, and decide to try your hand at your own limb designs, and get into recurve limbs, everything gets a bit more intense, and accuracy becomes mandatory. .010 can make 10 pounds difference in limb thickness alone on some designs…type of core material, type of glass, limb width profile,  and taper rates used , all come into play.  This can be as deep a rabbit hole as you make it, and incredibly challenging. Frustratingly as hell sometimes, but a lot of fun and satisfaction involved too….

Let the force be with you….. 

[Susquehannariverarcher]

I’m not sure what you meant by “starlightness” , must of been an auto correct thing on your PC….  But if you are talking about checking a form for twisting, there are a number of ways you can do this. The simplest method would be laying your form on a perfectly flat surface and use a square. Check your flat surface first with a straight edge diagonally from corner to corner.  Some guys just tape carbon arrow shafts on the form and eyeball it….

Unfortunately the forms that I have had twist in the past, I didn’t catch it until I was prepping the limbs for the riser. If you look at these photos you can see how I check the limbs for 90 degrees on a machined surface of the edge sander. It is perfectly square at the butt, the mid limb, and at the hook, there is no twist to your form. This is a perfect way to check your limbs prior to mounting them on a riser, and is critical for recurve limbs.

https://photos.app.goo.gl/KxYM6HaNonvtWqW86

Most bowyers get started with long bows that are more forgiving due to deep core narrow limbs are not so touchy about perfect alignment and tracking issues. You can learn all the other little tricks about tiller, and shaping tip notches and different types of grip shapes…. After you have the basics down, and decide to try your hand at your own limb designs, and get into recurve limbs, everything gets a bit more intense, and accuracy becomes mandatory. .010 can make 10 pounds difference in limb thickness alone on some designs…type of core material, type of glass, limb width profile,  and taper rates used , all come into play.  This can be as deep a rabbit hole as you make it, and incredibly challenging. Frustratingly as hell sometimes, but a lot of fun and satisfaction involved too….

Let the force be with you….. 

Awesome thanks for all the help. I'm sure I'll be getting back to you when I finally start.

And as far as long bows go I'm just going that route because I prefer shooting them.  Hopefully some day I'll be looking forwards to the challenge of making a recurve.

[Mad Max]

Checking the form to make sure the top is square to the sides.
This small gap can cause limb twist for recurves, look close at the pictures.
This is a riser block but same principle

[Susquehannariverarcher]

Checking the form to make sure the top is square to the sides.
This small gap can cause limb twist for recurves, look close at the pictures.
This is a riser block but same principle

Cool thanks. That's what I figured but always open to learn new things.

[Kirkll]

Yup.... Like Max showed above... If you can see light through it, it isn't close enough yet. A sanding block with 80 and 120 grit sand paper is your friendly fine tuner. There is no such thing as being too precise with building laminated glass bows.  This trade will take your patience and craftmanship to a whole new level.     Kirk

[Mad Max]

I bought a brand new DeWalt 1/2" router so I could get my forms square to the sides. $250.00
1st time I used it I had a gap, WHAT THE HAY, I was checking the router bit to base squareness, The Aluminum base plate was cast, I had to shim it to make it square. You can't get quality stuff any more.