[Irunbird]

Hi, all- I'm building this using panels of closed cell foam (Divinycell) and I've managed to sandwich three layers (1/2" thick and 12" x 60" width x length) and I'm not using a vacuum bag- just placing two long board with lots of weight on top, all of this laying on my garage floor in lieu of using sand bags as demonstrated on the Jamestown distributors videos. Anyway, since plenty of epoxy squishes out along the sides, I laid wax paper down, thinking that would work to keep it from adhering to extraneous surfaces, and it kind of does, kind of doesn't. I checked on it about 4 hours into the cure (using West System's slow hardener) and it still sticks.

Question 1: would using Saran wrap work better? I've also heard about using hair spray, but I'd be worried about not doing a sufficient enough job getting all the hair spray off and preventing a good bond when I wrap this thing with more cloth and epoxy resin.

Question 2: thinking about tiller options. I'm wanting to use aluminum tubing, and reading this: Guide to Buying Aluminum Online | Online Metals Guide to Selecting Metals for Your Project and here is where some selection comes in- I'm guessing that effective dimensions would be maybe 1/8" thick tubing, 1-3/4" outside diameter for a tiller that would be about 6 feet long, but I'd rather not just guess at this...

If anyone has any experience, especially with this last question, I'd certainly appreciate a little advice! This is for an Olson 30 (~3600 lb displacement), but my rudder is being designed more along the size of a J24 blade (which is approximately 3/4th the size of the Olson's).

Ray

 

[Alex W]

You could measure the tubing used for emergency tillers on wheel boats. Your guess of 1-3/4" by 1/8" wall sounds similar to what my Pearson 28-2 (twice the displacement of your Olson 30) uses, so that should be more than enough.

If you can figure out the max load on the rudder head you can also use beam deflection calculations to figure out the appropriate tiller tubing size.

 

[deniseO30]

wax paper as you found out is not good in contact with epoxy glue.. you did thicken the epoxy right? Anyway, polyethylene, like contractor trash bags, doesn't stick to epoxy.

 

[mitiempo]

Saran wrap won't work as it is too thin and weak. Thicker plastic is available by the foot in any hardware store and works well.

 

[hellosailor]

There's all sorts of "wax" paper sold. For cooking, baking, "butcher's" freezer paper...Whatever you use, there's a chance that some of it will adhere to the material or contaminate it with wax. Assume there is contamination and always clean before new bonding.

 

[mitiempo]

I have been using epoxy for over 25 years on various boat projects. Thicker plastic, say the thickness of a ziploc bag, works well and epoxy doesn't stick to it. There will not be any residue left on the epoxy surface from plastic as there can be from wax paper. On some occasions I have filled a surface with thickened epoxy and taped plastic over it to keep the shape and when it is removed there is virtually no sanding required.

You can download free the West Epoxy use guides here - full of good tips.
WEST SYSTEM | Use Guides

 

[hellosailor]

The weird thing with epoxy and tapes, is that if you put clear packing tape or any type of duct tape over epoxy, before it sets, it bonds incredibly well to the tape. I'd have thought it would just bond to the adhesive, leaving it bonded, well, like the tape had been stuck down on hardened epoxy. Nope. Damn near permanent. Who'da thought?

 

[deniseO30]

for small glue up. epoxy or wood glues.. and polyeth cutting board is handy

 

[mitiempo]

I agree, anything plastic works, as long as it is strong enough to be removed without tearing. Saran wrap isn't strong enough. The tools to work epoxy, from containers to mix it in to putty knife type products are all plastic and very re-usable.

 

[deniseO30]

Brian one of the best all time epoxy mixing cups comes from Chinese food soup containers. They seem to be a very soft Tupperware like plastic.

 

[mitiempo]

I use margerine containers.

 

[aeventyr60]

No, no, the best has to be tuna fish cans...

 

[mitiempo]

No, no, the best has to be tuna fish cans...

But they don't survive the flexing to get the hardened epoxy out.

 

[aeventyr60]

But they don't survive the flexing to get the hardened epoxy out.

If you poke a hole in the bottom you can string em together and make a home series drogue!

 

[Irunbird]

Thanks, guys! Tons of great ideas here. I talked with a friend of mine (fiberglass, paint guy, who does a lot of this work for a living), and discovered that I probably should have mixed in some high density filler (404) with the epoxy for my layers in between. I had planned on creating a groove and burying a length of stainless angle along the long axis, but he seemed to think that wasn't absolutely necessary as long as I thickened the epoxy for the outer layers of cloth that I use to glass the exterior of the rudder. I may still do that just to be absolutely sure. I could add one more layer with the 404 mixed in just to be sure...

 

[deniseO30]

You may want to check the bond between the layers of foam core, it may not have bonded because epoxy will "soak in" when not thickened. Best to find out now! good luck!