glass tape for Pygmy butt-joins?

[Rema1000]

</font> I'm assembling Pymgmy Boats' Wineglass Wherry.
Hull panels are in 8-ft sections which must
be butted together, and the joint covered on
both sides with glass tape, which is usually
very fine and thin (2 oz?). The lightest
tape I can get here in Minneapolis is 6-oz.
This shouldn't be a problem on the inside of the
boat, but may make a bump on the outside.
</font> I'm wondering if it is a bad idea to use 6-oz at
the joint, but add extra epoxy around the joint
to minimize the bump. I will double-glass the
hull exterior with 6-oz, so maybe it will not be
noticable under all that cloth.
</font> As an alternative, I have also noticed 'glass
companies selling polyester cloth; I wonder if
I could find clear polyester cloth at a fabric
store, and whether it would turn clear in epoxy.
</font> Or I could order the Pygmy stuff and wait a week (ouch).
</font> -Bradley
</font>

[John of Phoenix]

Hi Bradley.

"Or I could order the Pygmy stuff and wait a week (ouch)."

Do it right. You won't regret it. Trust me on this one.

[On Vacation]

http://www.imagestation.com/picture/sraid18/pe086d2534b1cd4146758e3c54f24e7cb/fdd35f27.jpg

[Todd Bradshaw]

It takes very little thickness to fair-out 6 oz. cloth, so you could probably get away with it. Most people have no concept of just how thin sheathing glass is. If you want to see for yourself, try laying up a couple layers of glass on a sheet of polyethylene or something that you can peel it from after it sets. Still, it might be smart to wait and get whatever the manufacturer suggests, just to be sure. Frankly, if it's 2 oz. I am amazed that they can make a decent butt splice with it. I am not aware of any polyester fabric that will turn clear in epoxy the way fiberglass will. Most of the synthetics like polyester and nylon get kind of milky white when saturated.

[Wiley Baggins]

I have to echo Todd's comments regarding 6-ounce cloth. I used it to splice 6mm plywood with the tape on both sides of the joint.

On the outer face (which received a paint finish) I beveled the "planks" (picture a shallow 'V') and incorporated filled epoxy and glass tape. For the inner surface, I used unfilled epoxy and glass tape (and no bevel). This surface was finished bright, and it looks fine.

Now, rightly, ignore this and do what the manufacturer says.

[Edit-I improperly used the term "tape" when referring to strips that I have cut from a roll of 6-ounce cloth. I should have thrown some quotation marks around the term, or been more specific in my description.]

[ 05-31-2002, 08:09 AM: Message edited by: Wiley Baggins ]

[JimD]

I probably wouldn't use tape. I'd be more concerned with the bothersome ridge the seamed edges of the tape will create. If you have 6 oz cloth I'd just cut a strip maybe 6 inches wide and let the edges feather, as long as you're comfortable working with a relatively narrow strip of unseamed cloth, which can be tricky).

[wolfietuk]

I will echo the 6 oz cloth can be feathered sentiment. Make sure you squeegee out as much of the resin as you can. But if you want some other cloth try fiberglass coatings inc. (http://www.fgci.com) They have great prices and prompt shipping.

Rick

[TomRobb]

I suppose scarfing is out of the question? :rolleyes:

[Tom Lathrop]

10 ounce cloth in epoxy measures about 0.020 so 6 ounce will be no more than 0.015. Except for the edge that always sticks out and needs sanding, it is pretty easy to fair.

[Wayne Jeffers]

A couple of thoughts:

1) Tom's right about this being easy to fair. Try a sharp plane set to make a fine shaving. Plane parallel to the tape, not across it. And if you're going to put more glass over it, it doesn't have to be perfect.

2) If you're going to cover the outside with two layers of 6 oz. cloth, the tape on the outside will be out of a job after that cloth goes on. Two layers seems excessive, however, unless there's some special circumstance. Really adds a lot of extra expense and weight.

Wayne

[ 05-31-2002, 06:03 PM: Message edited by: Wayne Jeffers ]

[LeeG]

I believe the tape is a high thread count 4oz weave. You can do the same with some bias cut 4 or 6oz. The tape is only there to hold the panels together long enough to stitch the hull together, even then is barely strong enough so handle the panels carefully. Polyester cloth will NOT wet out clear. If you are in a hurry and learning something new AND attempting something other than what is in the manual you're kind of setting yourself up for some expensive learning mistakes. I don't see any problem with using strips of 6oz then sanding the outside piece of glass down before glassing the hull.