To glass or not to glass

[Paulyboy]

I've been reqading this forum for a while now, and it seems there are a multitude of very experienced professionals that contribute here. Some of you are pros in building or restoring, some are pros in the businesses that supply the materials used in building. My question is this- if I'm going to build a light, 20 foot or under boat that can be rowed or use a small engine, should I layer it in glass, or just u se epoxy as adhesive and paint and seal it well? I'm going to be using ply, but my next project will be a stripper style square end canoe large enough for my considerable bulk.

[JimD]

The pros may have quite different opinions on this subject. I am not one of them, but my opinion based on personal experience is that you should glass it or use some material other than fiberglass.

[Tom Hoffman]

Pauly, I am in the process of building the same kind of boat, for the same reasons, and I am of CONSIDERABLE BULK too. I am actually just short for my weight. I should be 7'5" instead of 6'5".

I am building a Whitehall Stripper stretched too 20' from 17' This is my 3rd boat all strippers, I have never tried a ply boat. probably would be easier, but I live in and area (Iowa) where good boat building ply or lumber is at a very high preimum.

I manaaged to find some Western Red Cedar left in an old lumber yard here local, but even then it cost $50.00 per board 1X6 20' Needed 11 boards to build.

I am posting the link so you can look at mine. It should be a good boat for recreational rowing and able to put a 2-5 hp motor on it if I want. Should be fairly shallow draft for the shallow rivers and steams we have here.

http://community.webshots.com/user/slvrgost

Here is another link to a free boat plan that I have thought about doing in Ply.

http://www.svensons.com/boat/?p=MechanixIllustrated/Pod

[Dale R. Hamilton]

Paulyboy- To glass or not to glass depends largely on how/where you will use the boat. If it will live out of water, and you will use it in lakes and rivers, glassing will only add needless weight/expense for no real gain. On the other hand, it you will be leaving it in the water, or exposed to the elements, you need at LEAST epoxy saturation, and at best glass cloth AND epoxy. Moreover, it you will be using it in streams where its subject to rocks and shoels, you need the abrasion protection that glass affords. The more glass/epoxy you add, the more protection (and weight) you gain.

[Paulyboy]

Dale, well put. I'll be using this mostly in small lakes, rivers, and I"m aspiring to someday go back to my native Brisol, R.I. and put it in some of the old salt water, but it would live mostly out of the water. I'm planning on using some fairly thick cloth as a protectant under the water line, and I would think saturating the wood with very thinned epoxy would help the rest even without cloth. Whattya thank?

[Bruce Hooke]

Using glass makes it more viable to use "relatively" inexpensive Douglas Fir marine plywood, because a good layer of glass cloth on both sides keeps the wood from checking. On the other hand, if you use higher quality, hardwood marine plywood then glass is less necessary. If kept painted and well maintained plywood can stand up just fine even in a boat that lives in the water. The most important areas to protect are chines and similar places where the very vulnerable end grain of the plywood is exposed.

[Tom Hoffman]

I guess I did not say it, but my Whitehall is going to be glassed inside and out.

My two canoes I made back in the early 80's are over 25 years old now and both were glassed inside and out with epoxy, 6 oz glass cloth and today, they look as good as new. Virtually no maintenance has had to be done on either. The extra weight on a boat like this would be minimal.

In the Cosine Wherry book he goes to the point of putting 1 full layer, one 2/3 layer and 1/2 layer all centered over the keel, thay way you have 3 layers on the keel and both sides of the bottom just up past the water line, then two, and then one up by the gunwale.

Just another way to approach it. I am only putting one layer on mine with a few inch overlap over the keel, and then 6" tape over the keel and 3" tape over the corners of the transom where it joins the hull. Then 6 oz through out inside.

[paladin]

I would use Dynel...or actually prefer Xynole fabric as opposed to glass...better abrasion resistance and lighter.....

[Dale R. Hamilton]

Pauly- can't add much to what I've already said- but consider System Three Clear coat. Thin, colorless, excellent penetration, AND- you can finish it bright- right over stain. Look up my thread "Progress pix, Ray Sargeants Runabout" in Building/Repair last week, and look at the tansom in the pictures. Don't think you can tell the epoxy finish from 9 coats varnish finish.

[RodB]

If building with ply, glass it inside and out. At a minimum, glass any surface that will be exposed to sun, and elements... double coat the other surfaces with epoxy. Reinforce the bottom where abrasion will take place. Xynole is much better for abrasion than fiberglass but will take perhaps 50% more epoxy to saturate and cover the weave. . . very strong durable sheathing.

Glassing will increase durability, longevity and decrease maintenance immensely. It may be a bit more work, but the boat will be around and in great shape for a long time.

RB

[ 06-20-2005, 02:38 PM: Message edited by: RodB ]