Trilam Build Questions

[Exiled_Archer]

So I would like to try a trilam...it'll by a try-lam. Lol. Okay sorry for the bad joke.

So anyway, I am wondering on how is my best approach.if nyone who has done this could chime in, that'd be awesome.

I am thinking of doing hickory back, maple core and ipe belly.

With this, how do I go about grinding and setting up for the build? Do I keep a 1/8 back for my hickory, 1/4 maple core, and then the rest ipe? Glue it all together into a solid board and then work it as if it is a board bow?
Or do I profile and taper the lams before glue up?
And do I just use titebond or am I screwing up by not using epoxy?

I only have tbb 1 and 2, so not sure if trilams are covered in later episodes or what. If someone has a good resource, that be good too.i know I'm asking a bunch of stuff here.

Thanks for the help guys.

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[TradBowyer]

i just glued on up today. we went with a 1/8" hickory backing, 3/16" tapered core and 1/4" belly slat. This was glued into a D/R style and should come out in the 50s# range. never did a hickory backed tri-lam so we will see what happens

[Exiled_Archer]

So you rough out the profile and taper as if it was a laminate glass bow? Epoxy glue up and just do the finish work when done?

So no tillering after glue up?

Seems like without glass, the tiller would be a crap shoot.or am I overthinking it?

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[Bowjunkie]

Leave the lams full width, like when building a glass/wood laminated bow. I taper the core lam from dips to tips, belly lam is parallel. Glue them into whatever side profile you like. Then after it's cured, take it out of the form, clean up excess glue, then fit up and glue on the handle piece. After that's dried, shape it and tiller it. Yes, these bows are tillered like a selfbow by removing wood from the belly and/or sides.

The draw weight is 'ballparked' by the thickness of the lams, but since there's no glass in the way, weight can be reduced by removing wood from the belly as well as the sides.

[BMorv]

Darn, I was going to tell you to read through some of Roy's builds, but just realized the new website obsoleted all of the old stuff.  This kinda sucks.  I have a lot of saved builds from the old site that I reference.

That's a good choice of materials you have.  It should work fine if you have quality straight grain hickory and ipe. 
Glue up your lams full width with the profile drawn out on the backing.  It's almost impossible to draw out an accurate profile if you wait till after you glue in r/d.
After glue use the bandsaw and cut out your profile.  Add a riser and tip overlays, round off edges, facet everything, and start tillering.  You will have to tiller these some unless you have done some experimenting or you follow to the T the exact recipe someone else did, and even then you will have to do some tillering to even the limbs and balance it to your style of shooting.  On your 1st try go a little thicker on the belly, like .050" more than you need so that you have room to play with.  It took me 5 tries before I was able to predict the right recipe, and I still have tillering to do.  Just not as much as lets say a self bow. 
Taper your lams before glue up. I use .002 "/inch on all three lams for a total of .006"/inch taper.  Some guys don't taper the belly and just do around a .004"/inch total taper.  I like my tiller to look more like an arch because I use a straight pyramid that's why I use more taper.  Up to you on that. 
 
 

[BMorv]

Bowjunkie beat me to it.  Most of what I know about tri-lams came from him and Roy, so anything conflicting between our statements, his word trumps mine...lol

And check out BB4, laminated bow section.   Mike Westvang builds an awesome bamboo/osage/osage tri lam.  Maybe not the best for a beginner as he puts a load of reflex in his, but you get a lot from the process. 

[Exiled_Archer]

Thanks guys. That's what I'm looking for.

So glue up. What's your glue/epoxy of choice?

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[BMorv]

Uni bond 800 is the best for tri lams imo as well as others.  Get if from Vacuum Pressing Systems, Inc if you do get it. 
I've used Weld wood plastic resin also and it works well. 
TB3 would work, but it has no gap filling properties.  I've used it a lot on single lams and it works fine. 

[Ruben]

Darn, I was going to tell you to read through some of Roy's builds, but just realized the new website obsoleted all of the old stuff.

Fyi,
 All of the old posts or at least 99.99999% of them are intact.
It is just old links and bookmarks refer to the old site links so they don't work to find them.

I don't know which Roy you are referring to but if you search this site they should all be there.
Give it a try.

[BMorv]

Ruben,
The user is "Roy from PA" and I've search 4 different ways now and I can't pull up any of his builds.  I hate to be so critical as I'm sure there was a lot involved in making the new website, but the new search feature isn't very good. 

[Ruben]

Understood.
But since I don't have any clue what to search for, here are all of his posts.
http://www.tradgang.com/tgsmf/index.php?action=profile;area=showposts;u=10116
Easy for anyone to find.
See if you can find what you are looking for then use the search.

[Bowjunkie]

I use Smooth On ea40 because I always have it here and use it for most of my bow work, and all sorts of other things. If I didn't have it, I'd use Unibond 800.

BUT, the best glue to use on a trilam should largely depend on the gluing surfaces... or is it the other way around? Same result I guess. Lol. I grind my parts with 40 grit, and prep bamboo, handle, and overlays with a toothing plane blade, so I want a glue with good gap filling properties. Perhaps your gluing surfaces will be much smoother, in which case you may want to use Titebond or something similar.

[mwosborn]

Darn, I was going to tell you to read through some of Roy's builds, but just realized the new website obsoleted all of the old stuff.  This kinda sucks.  I have a lot of saved builds from the old site that I reference.

The search feature is a little different and takes some getting used to, but it does work.  Same format used on other sites.  Here is one of the builds Roy posted a few years ago.  Hope the link works.

http://www.tradgang.com/tgsmf/index.php?topic=155065.msg2680182#msg2680182

[Exiled_Archer]

Do I need a heat box for unibond like would for smooth on? Or does it work just as good at room temp?

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[BMorv]

All you need is 70 deg and it will cure.  I normally put it in a bathroom with a space heater and leave it over night.   

[Exiled_Archer]

All you need is 70 deg and it will cure.  I normally put it in a bathroom with a space heater and leave it over night.

Sweet, thanks. That's even better

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[Exiled_Archer]

Okay so maybe this is the last of many more questions. Lol

Sourcing this material, how cautious do I need to be with grain violations on the belly and core materials?

I know the hickory backing needs to be good and straight, but what about the other layers? I mean is anything short of burl wood gonna be okay? Or what?

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[Roy from Pa]

Mwosborn posted a good link to one of my builds..

This one>>>----------->     http://www.tradgang.com/tgsmf/index.php?topic=155065.msg2680182#msg2680182

Back and belly you want very good straight grain, very little run outs.

[BMorv]

Try your best to stay away from anything with knots or swirly grain, even for the core.  Your best bet is to get your lams from someone that knows bow wood, and only sells lams suitable for a bow.  KennyM is a good source for cores and osage belly lams.   Kenny's custom archery.  He's a great guy to work with too. 
If you plan to cut your own from boards, you want to be very picky on board selection.  I recently went through a stack of 100 ipe boards an came back with 1.  Your bow is only as good as the materials it's made up of. 

[Roy from Pa]

Yup Old Kenny is a great guy to deal with..

Little orenery, little goofy in the head, little.. Ah heck I guess he is ok:)

https://www.kennysarchery.com/