Advice needed... (modifying amas for Triak)

Stitch and glue ama mod...

OK, if I can substitute polyester whipping cord for the wire stitches, how to I tighten...or am I misunderstanding what the wire stitches are doing. I thought you twisted the wire to provide tension to keep the parts together while the epoxy cures, like being clamped since clamps wouldn't work. I am trying to get a flat piece to bend to conform to a curve.

Also, I'm not planning on a flush butt joint between the spacer and the two halves, I'm planning on having the spacer inside the two halves and pulled to the walls with the stitches and glued in place. Will that be horribly wrong? That way, my "less than perfectly straight line" when I cut the float in half can be finessed in the finish glasswork.

One other thing, I am buying a sheet of frp since it is even thinner and more maleable than 1/8" ply and should conform to the hull shape better. It is used to line showers, so I"m pretty sure it is "out of the box" waterproof and should take additional glass on top without a hu-hu.

I appreciate all the advice--please let me know if I'm wrong headed about this.

 

I would suggest also xps sheet foam.

Cut as you did last time, make as straight cut as possible.
Pancake couple of layers of 2" xps foam
make vertical air passages throug this foam stack.
Keep foam stack slightly over sized compared to the fiberglass halves from old floats.
Once the top and bottom halves are glued to the foam stack, shave and sand to match the original float bits.
Roughen up old bits and glass over with epoxy.
Use epoxy for everything here. Use colloidal silica or other fillers where it makes sense to thicken the epoxy.

Should be way easier than making new floats

 

XPS foam

I had thought of that method but was going to put the foam inside the two halves mounted on flanges, I hadn't thought of reglassing the entire float, I was only going to glass over the middle insert--thereby saving the existing gelcoat...but that's not important. This seems do'able with my limited skills.

But that's what I started this thread with...stitch and glue also seems within my limited skills.

 

I would't necessarily glass over the whole old float but a good overlap for sure. You can fair the extra thickness of the glass quite well. Just make sure any exposed fibers get eventually covered by epoxy.

 

I found some polystyrene in the insulation section of my local Lowes. One sheet per float will give the needed thickness. But, it is covered with a vapor barrier front and back. Does anyone know how hard that barrier is to remove before I buy? Also, should I get a foam cutter (hot tool to melt through the polystyrene). Thanks in advance.

 

Look farther for bare foam. I know you said it's tough to find, but cutting off the barrier will be hard.

A hot wire is difficult to set up and use the first time. You will need a long bow and a good adjustable power supply.

The cut surface is not nice and flat unless you have lots of experience - and then you will probably have to sand it.

IMHO.

Aircraft Spruce and Specialty has extruded foam - http://www.aircraftspruce.com/menus/cm/foam.html

 

Turns out that the barrier that they put onto the front/back of the standard board insulation is pretty easy to remove. It appears to be tyvek or mylar and peels off with limited effort. I tried a hot knife at first for cutting, couldn't get the precision I wanted so I went to a jig saw and that worked OK. Styrofoam sands easily so I just cut a rough outline and sanded down to the dimension I wanted. I'll be glassing over the weekend. I'm using 6" E glass tape and will cover it with a 0.9 oz veil and West system epoxy. I'm not going to use gel coat and will just sand and paint. Thanks everyone for your help and suggestions.

 

Glad you could get the barrier off easily.
Just shows you get what you pay for (advice that is!)

Pictures would be fun.
Good luck.

 

The forum limits photos in jpeg format to only 2 megs. That's pretty small anymore. But I will provide some if I can figure out how to reduce the image sizes.

I do have another question if anyone would provide advice. The edges of fiberglass tape are raised. Not an issue if I wanted to sand them down and I might do so. The veil fabric, though, takes an awful lot of epoxy and any slight rise (like the tape edges) cause voids. I'm wondering if it is worth it to add the veil. I can live with imperfect results with just the e glass painted, I just wonder how much (if any) structure is added by adding the veil cloth.

 

Veil is not required for epoxy. Polyester needs it.

You still need to fill the "weave" in the glass, and a raised edge on the tape requires even more fill to get a smooth surface. Once you get the weave filled - mostly - go ahead and sand the raised edge gently. Then coat again to get enough epoxy to sand without cutting into the glass. You could do the final fairing/ fill will a filled epoxy, since you will be painting the hull.

 

Thanks.

 

Oh, rather than shrink photos to attach here, I've been posting photos as I go along at the Triak forum. You don't need to be a member to browse. Here's the topic..http://trisailor.com/index.php/foru...s/50-float-enlargement-2-begun-today?start=12