54" Hybrid Build-Along

[goobersan]

Thank you Jon. So many tips and tricks I never thought of    

[JGR1269]

No problem guys. I think everyone should do a build along and share their secrets. We all benefit from others knowledge.

[JGR1269]

The power came back on but it was too late to glue up tonight so I prepped my bench with some freezer paper and laid out my glass and lams for glue up. I put a fresh layer of tape on the aluminum pressure strips and they're ready to go.

I never really cared for the tape down method so I drilled holes through my form to run zip ties through for holding everything down until the air hose is inflated. I'll show how I do this during glue up.


Hopefully at this time tomorrow I'll have a bow in the oven curing.

[JGR1269]

I got home from work tonight and turned the oven on so it would be up to temp when I finished the glue up. I mixed up the Smooth-On and put it in the oven to warm up while I put a layer of plastic wrap on the form.


I mixed up the Smooth-On and it's time to start spreading.

Once the back glass and taper are covered I stack them and place them on the form. I glue up the back and belly ramps on the riser and place it in position on the form. Now I glue up the top and bottom belly glass, taper and CoreTuff and stack them on the bench.


I stack the belly lams on the back lams on the form and slide the ends of the limbs under the metal strip and up tight to the stop.

[mwosborn]

Nice build along!

[JGR1269]

Next I clamp the riser into position making sure my center marks are lined up and it is up against the side stops on the back side of the form.


I put another layer of plastic wrap over the lams and slide the aluminum pressure strips under the metal strip on top of the lams and against the stops.


Now I can start running the zip ties through the holes in the form and over the pressure strip. I pull them down as tight as possible working from the tips towards the riser.


I check the riser again to make sure it's still centered and against the side stops on the back side of the form.

[JGR1269]

I remove the clamp and allow the zip ties to hold everything in position.

I lay the air hose on top of the pressure strips and attach the upper half of the form to the lower part.



I inflate the hose to roughly 20 psi, check that everything is aligned and wait a few minutes before inflating it to 70 psi.


I check that everything is good and place the form in the oven for four hours.

Tomorrow after work I'll pull it out of the form and see if I did everything right.

[chall]

[Sam Harper]

Very cool build along!

[stack]

Very nice, at what point did you pull the zip ties out? after you got to 70 psi? I really like this idea tape is a pain.

[JGR1269]

I don't pull them out. There's no need to because they are on top of the pressure strip.

[JGR1269]

My pressure strip is .080 thick aluminum so there is no issue of them putting marks in the limbs from the pressure on them.

[chackworth3]

Still looking great!

[Mad Max]

Can't wait to see what it's going to look like

   

[bigbob2]

Using lighter gauge pressure strips I had the ties leave marks in the glass even though I cut the ties out once I get the air pressure up to about 20 psi. I might have to go with heavier pressure strips like you have done.

[bigbob2]

terrific build along too by the way!

[kennym]

Lookin good Jon!!

[JGR1269]

Fresh out of the form.



It looks good and straight with no twist.



I measure 28" each way from center and mark the overall length. I'll reduce this slightly when I do the tips.



I measure 1 5/8" from the back glass to the throat of the grip.



I use my old recurve grip template to mark the curved shelf.



Now it's off to the drill press. I clamp the riser in the vise and make sure it's level both ways.



Using a brad point bit I drill a 3/8" hole all the way through the belly glass and this will be where my shelf meets the sight window as well as the high point of the shelf.



Next, with a Forstner bit, I'll drill a 1 5/8" hole through for the throat of the grip.

[JGR1269]

Now I can make the cuts for the shelf, sight window and grip profile.

[JGR1269]

Tomorrow I'll get the limbs cut down to rough width, string it up and check tiller. I'm shooting for 48-51 pounds at 27" with an even tiller for my three fingers under release.