Glue Up Process

[D.A. Davis]

Ok guys, I've been reading and looking at everything I can on bow building on this site and others.  I'm almost to the point that my shop is ready for me to start building my first bow.  I've written up the process, as I understand it, to the actual glue up of a laminated bow.  Look through it and tell me what I've missed, or gotten wrong.

Bow Building Glue-up Process Order of Steps

1.   Prep riser woods
2.   Check riser components for proper fit
3.   Mark riser center line
4.   Pre-heat riser woods before assembly at
        150 degrees for one hour
5.   Spread Smooth-On on both sides of riser
        woods to be glued
6.   Make sure riser woods are lined up with
        center line mark
7.   Clamp riser wood pieces together firmly
8.   Place clamped riser in 180 degree hot
        box for 6 hours, minimum
9.   Turn off hot box and allow to cool slowly
10.   Remove riser assembly from hot box when
        completely cooled
11.   Cut angle-butt joints on each parallel
        and glue up with Epoxy
12.   Wrap with plastic wrap and clamp till dry
13.   Unclamp and unwrap parallels, lightly
        sand off excess glue
14.   Lay out limb laminate pieces for dry run
        on assembly
15.   Prep bow form
16.   Apply blue masking tape to bow form
        surface
17.   Cover bow form with plastic wrap
18.   Apply second layer of plastic wrap for
        use to wrap bow with
19.   Apply blue masking tape to glass
        laminates outside surface
20.    Perform dry run in the following order
A.   Back glass laminate tape side down
B.   Parallel
C.   Parallel
D.   Parallel
E.   Riser assembly
1.   Line up riser centerline with bow form
        centerline
F.   Tapers
G.   Belly glass laminate tape side up
H.   Apply metal compression strips
I.   Rotate off-set side washers to proper
        height
J.   Install fire hose
K.   Install bow form top half and secure
L.   Pressurize fire hose to 70 pounds
M.   Check for proper fit of all glue lines
N.   Disassemble in reverse order
O.   Make necessary adjustments to glue
        lines, if necessary
P.   Perform second dry run, if necessary
21.   Rough up laminates glue surfaces with 50
        to 80 grit sandpaper
22.   Place all laminate components and riser
        assembly in hot box for preheat before
        assembly
23.   Preheat at 140 degrees for one hour
24.   Remove all components from hot box and
        lay out in proper order for assembly
25.   Apply Smooth-On to uncovered side of
        both Back and Belly glass laminates
26.   Apply Smooth-On to both sides of each
        parallel and taper
27.   Make sure to keep components laid out in
        order of assembly
28.   Begin assembly in the following order
A.   Back glass laminate tape side down
B.   Parallel
C.   Parallel
D.   Parallel
E.   Riser Assembly
1.   Line up riser centerline with bow form
        centerline
F.   Tapers
G.   Belly glass laminates tape side up
H.   Apply metal compression strips
I.   Rotate off-set side washers to proper
        height
J.   Wrap second layer of plastic wrap over
        all components in bow form
K.   Use tape to hold laminates in place by
        wrapping bow and form in key locations
L.   Install fire hose
M.   Install bow form top half and secure
N.   Pressurize fire hose to 70 pounds slowly
        to allow for excess glue to squeeze out
O.   Take decal squeegee and wipe excess glue
        down off of bow
29.   Place assembled bow and bow form in hot
        box and heat at 160 degrees for 8 hours
30.   Turn off hot box and allow to cool
        slowly before removal

[sulphur]

only two things i see. Why 3 parallels???  You'll get a better shooting bow if you use at least 2 lams tapered at .001.  60 psi is plenty of pressure.  looks good though.  always good to have a plan.

[TNstickn]

Also, use a bicycle pump and go 10 lbs or so at a time, give it a minute and fill 10 more lbs. It gives you the time to watch for slippage and lets the glue slowly ooze out reducing the chance of a dry spot or bubbles. There is plenty of working time with smooth-on, be patient, dont rush your self through and it will turn out great!  

[bjhaug]

Dont forget, warm smooth-on!  I let it sit in the box for about an hour or 2 before I glue it up.  Makes it very viscous and, in my opinion at least, easier to use.

[Apex Predator]

If you get the smooth-on too hot it can set it off somewhat.  I did that once and was racing the clock to get it all laid up, and it was getting pretty thick towards the end.  This time of year, I think I would skip pre-heating the epoxy.

[bjhaug]

True Story:

This past winter I was out in the shop getting ready for a glue up.  I wanted the smooth-on to be workable so rather than wait all the while for it to warm up in the hotbox, I just put it on the top barrel of the 2 barrel heater out there.  Well there was a good fire in the heater and not 8 minutes went by and I had burnt the bottom of the cans.

Well the show must go on so I went ahead and used it.  It was almost like water.  But Apex brings up an excellent point that I neglected to throw in my first reply.  When I mixed the two parts, it instantly got hot and melted the plastic cup I was mixing it in.  It was the strangest thing.  Still though it was like water and I was able to literally pour it on at any rate I wanted to, smear it around and get going.

So yeah, uh dont do that