looking for input

[Rodroo]

I am contemplating building a boat but am facing a few obstacles/limitations and need some input.

I have a done a fair bit of reading on this forum and know the prevailing views on epoxy vs polyester resins. Having said that I am still wondering about building using polyester resins.

Let me layout my limitations first and then I will get around to my ideas and that is where I will need some input. I want to know if this is workable or not advisable.

I am living in east Africa and marine plywood is virtually unavailable. It can be had at great expense in limited sizes and with limited guarantee of quality. Secondly, epoxy is available but once again outrageous prices as it has to be shipped in and there are heavy taxes on all imported items. I can get cloth and matt easily as well as polyester resin.

So here is my idea. Build the boat (an Argie 15) with local plywood and go with thinner than specified plywood. Knowing that the ply is cheap crap, I would then glass the entire boat, inside and out using polyester resin and fiberglass cloth. I would add in extra layers at joints and would also consider multiple layers on the exterior.

Basically, I would be building a fiberglass boat and leave the mold/form inside of it. I am not trying to re-invent the wheel, just work around my limitations of material and finances.

Is this workable?

What are the shortcomings of this method?

Are there alternatives that I am missing?

Thanks,

Rodney

[CatBuilder]

I think the major question is:

How long would you like this boat to last? What is your expected service life for this vessel?

Also, are you able to get the same epoxy as people in Egypt? I remember Vulkyn found some excellent local epoxy for a good price there. Not sure if there is trade and commerce between Egypt and Kenya.

Another thought: Why not just make a fiberglass boat if you are going through all the trouble? Could you make a mold or plug, use mold release and pop an all-fiberglass, polyester boat out of it? I know it's a lot of work, but based on your limitations, it might be a way to get a long lived boat with the materials you do have on hand.

[gonzo]

As long as there is no water intrusion in the laminate, it should give you a reasonable service life. If the boat will be out of the water most of the time, it will last you a lifetime.

[Rodroo]

Gonzo, I am not sure how to take your comment... The boat would be stored out of water and would probably see water less then one day a month.

Catbuilder, to be honest, I really don't know were to start if I were to go the route of making a mold. I had one guy recommend putting together a form, lining it with cheap laminate such as you would put on your countertops, waxing it well and then glassing the inside of that mold. Is that similar to what you are thinking?

As far as trade and commerce between Egypt and here, it happens but not on a large scale...

A few days ago a had a really good chat with a fellow from a local commercial boat yard. He was very helpful and encouraging with my building my own boat as he did not really have anything to offer me. Anyways, it was from him that I finally found my source for epoxy. Up to that point I was coming up empty in search for epoxies of any sort.

Rodney

[CatBuilder]

Replying inside your previous post... read down...

Originally Posted by Rodroo

Catbuilder, to be honest, I really don't know were to start if I were to go the route of making a mold. I had one guy recommend putting together a form, lining it with cheap laminate such as you would put on your countertops, waxing it well and then glassing the inside of that mold. Is that similar to what you are thinking?

Yes, exactly. A "mold" just has to be something sturdy and very "slippery" in the shape of a boat. It can either be male or femald and you could lay up the fiberglass and polyester resin on that mold. The idea is to really make it slippery with mold release wax, so your boat can be easily freed from it. Not sure if this is something you want to do, but I was thinking it would produce a high quality boat with no structural defects, using the materials you already have available.

But, since you said the boat will be stored out of the water and used infrequently, I'd say Gonzo is right.




As far as trade and commerce between Egypt and here, it happens but not on a large scale...

A few days ago a had a really good chat with a fellow from a local commercial boat yard. He was very helpful and encouraging with my building my own boat as he did not really have anything to offer me. Anyways, it was from him that I finally found my source for epoxy. Up to that point I was coming up empty in search for epoxies of any sort.

Rodney

[Rodroo]

Ok, thanks for the input guys.

After my last couple of experiences with hiring boats for fishing and such, I am ready to have something of my own that I can use MY time frame, as I want to, and do with as I please.

Looks like a new project is in store for me!

Rodney

[cthippo]

I don't have any direct knowledge, but I remember PAR mentioning a number of times that getting polyester to stick to wood is nearly impossible. You might have to coat the wood with some sort of paint, maybe an epoxy paint or a polyurethane, before the polyester will stick to it.

[txriverrat]

I have ten different kayaks I built from polyester and use them hard. The only reason I use epoxy now is because the poly is the same price.
Ron

[gonzo]

Most production small to medium powerboats have polyester over wood construction. They last twenty years or more with minimum maintenance. The usual culprit for rot and delamination are the holes made later for accesories, wiring, etc.
Rodroo: for a boat that is sporadically in the water, polyester is just fine. I have built several skiffs out of cheap plywood and polyester, with only the seams glassed over. Left outside they last about three years. That is with no extra painting or maintenance.

[Rodroo]

Very cool, I am starting to mentally gear up for this. Due to my schedule, I will probably not start for awhile, but it sure is fun to start thinking it out and tweaking the design (internal seating and such small stuff) in my mind.

Gonzo, thanks for clarifying. I was unsure if there was some good-natured tongue in cheek sarcasm or if you were referring to type of storage.

[LP]

I'm not a knowledgeable polyester guy, but I think your primary concern is in the preparation of the substrate. There are stories of polyester delaminating from wood and ply and it was trace to a lack of knowledge about surface prep. Epoxy is not so critical.