Glen-L TNT

[rgardn12]

I am planning on building the Glen-L TNT... I am trying to do it on as much of a budget as possible. I am currently trying to get the plans ASAP, so I can start figuring out what type of wood, how much, and where to buy but I don't think I am going to have as many problems buying the wood as sealing the boat...

Are there any alternatives to laying fiberglass on the boat's hull to keep it from rotting? it seems to me that laying fiberglass is one of the most expensive parts of the work.

[apex1]

Originally Posted by rgardn12

Are there any alternatives to laying fiberglass on the boat's hull to keep it from rotting? it seems to me that laying fiberglass is one of the most expensive parts of the work.

Unfortunately not, glass Epoxy is the material of choice if the boat has to last for more than a summer. This issue has been discussed here several dozen of times. If you use the search function you will get more valuable information about it.

Regards
Richard

[marshmat]

Fibreglass and epoxy do tend to be a major contributor to the cost of this type of boat.

Unfortunately, there aren't any cheaper alternatives that make sense. You can use polyester resin instead of epoxy, and save a few dollars. But I wouldn't recommend it- it's a major hassle to get it to cure properly, and even then it won't necessarily stay adhered. I've done it successfully (my own boat is glass/polyester over plywood) but I would not do it that way again; epoxy is much less of a hassle.

Not glassing is really not an option. The fibreglass skin is part of the structure of the boat, as well as being a protective covering. Leave it off, and the boat probably won't break up on the first trip, but it'll deteriorate very quickly- a lifespan of maybe a couple of years.

[rgardn12]

thats fully understandable... I have a question though. I was looking on Fiberglasssupply.com at the Silvertip epoxy system, it says that it can be used with fiberglass, graphite, kevlar, and bare wood. Does this mean I can hold off on buying the fiberglass cloth itself and just buy the epoxy to use? or does that compromise the structural integrity?

[PAR]

Epoxy is a multi purpose resin. It's used as a glue, a fairing compound, a filleting material, fastener/hardware bonding, a surface coating and to wet out and adhere fabrics to things (like boat hulls).

Epoxy resin alone as a coating will form a tough plastic coating on a surface, but it can be greatly improved with the use of reinforcements. These reinforcements are the key to good epoxy work.

Fabrics of many types (like 'glass cloth or Kevlar) are a reinforcement as are the many different powders that can be mixed in. Each imparts a specific set of physical attributes to the cured matrix. Using the proper ones makes live a lot easier, the epoxy as tough as necessary for the tasks you'll ask of it and improved performance from it's use can be expected. Your design has no need for fancy fabrics like Kevlar or carbon, so don't waste your money.

To answer your question, don't skip the cloth aspect of sheathing the boat. Epoxy alone will offer little abrasion resistance, particularly compared to cloth saturated epoxy. The reason you'll be applying the sheathing (cloth) to the hull of your TNT is for abrasion resistance and waterproofing. The TNT doesn't need, nor does it get much, additional strength from the fabric sheathing, but it does help the wood survive bashing into docks, trailers, ex-wives (if you're lucky), etc. On the inside of the boat you'll also use lots of epoxy. Follow the plans and the guide lines at the Glen-L site and you'll do just fine.