Was saving money a mistake? (Epoxy vs Vinylester) | Step 403

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Now that your test is finished..... I am an architect and after the crash in 2008, I was fortunate enough to find a job as a forensic architect. I needed to measure the force for a pull test on an exterior floor coating. I used a fish scale. In any case I believe you conclusions are sound enough for you purposes for a couple of reasons. 1. You have greatly reinforced the hull with the ribs and 2. You are connecting the bulkheads to the hull/ribs which they were not before. Actually, in the first test you really only tested the strength of the plywood glue but the two coating did not fail first. The in hull tests were interesting eng helpful for you. None of the tests tested shear which will happen at the ribs to hull joint as the hull flexes. In any case, I think, for you boat and the stresses it will experience it will work fine. Good lunch. I really enjoy watching eng respect you both. George

When I bought my first sailboat I met a glass guy from Canada that used vinylester almost all the time. He extended his boat by a few feet for a sugarscoop. That stuff was fantastic!

Once, when researching problems with osmosis, I read an article that said you should always have the least porous materials on the outside with progressively more porous material as you move inward to avoid trapping moisture as it moves through the hull. Trapping moisture in the fiberglass layup leads to delamination. Epoxy is the least porous, so should be used on the outside with more porous materials such as poly ester and vinyl ester used on the inside of the hull.

We have had similar arguments with people whilst we are rebuilding our Trimaran. As it was built out of Polyester, but everyone cries about using epoxy for everything etc and how we are doing it wrong by using polyester. Sure we use epoxy for specific things, but for general repair work, polyester is brilliant and extremely cost effective.

When saturating plywood it's worth noting that it will only penetrate as far as the first glue line, so bear that in mind when a strong joint is needed.

Its not about adhesion only. The main reason to choose epoxy vs vinyl resin - it gives you more rigidity for same amount of materials. That means it is only choice when "weight" is crucial. So if you going to build racing-boat - it is crucial if it weight 1000Kg for epoxy or 1100Kg for vinyl

This is very educational and gives rise to new developments in the industry. You were also one of the first adventurers who went with an electric motor and electric boat!

Your crane analogy answers it perfectly!

The tabs in your bilge broke the epoxy join as you were using ply as leverage, so it wasn’t the glue strength on the ply, it was the sheer strength of the ply vs glue strength of epoxy. I tested maybe 20,000 pieces of plywood for my graduate study. The phenolic resins in plywood are WAY weaker than any glue you are using, so results expected. Ply loses massive strength when soaked for 24-36 hours, sealing your ply protects your bulkheads. Looks like your intuition & budget were right on the money.

I loved the analogy of the two cranes to lift the boat, perfect. Both resins would work in the situation so why spend more on the more expensive resin. I also understand why you chose to go with epoxy to layup the plywood the "better" penetration into the plywood is a factor apart from the resin strength. I also agree with the comment below on coating all surfaces of the deck sole mounting blocks with epoxy to prevent rot. Loving this in depth rebuild.

Vinyl ester resin is basically a hybrid of polyester and epoxy resin. Its design to give the fast curing and working time of polyester with superior bonding and water proofing properties of epoxy. Thats why you got very similar results between the ve and epoxy. You're made a good choice, carry on. 👍

It's always good in a build to save money where possible and where it doesn't affect the strength. You will be sure to spend the savings somewhere else.

I had a read through the ingredients for Magic Mind. There is caffeine in that product. It also has matcha which is a green tea...which your body will convert to caffeine (I believe) but the release is slower. Either way, it will prevent the caffeine crash. If you love it, keep using it. The other ingredients are good for immunity and stress. Now for the Epoxy vs Vinylester debate, I have nothing to add. Never used either and we aren't boaters. :)

6:48 An excellent penetrant can be made by mixing 50/50 automatic transmission fluid and acetone. It’s a bit messy, and cannot easy be sprayed, but it’s cheap and works VERY well

There is always a weakpoint if it is not one homogenous moulding. I get "non-brand" epoxy for the same price as vinylester , which is the only reason i use epoxy when bought in bulk. I also use D3 rated wood glue, which is also stronger than the wood it bonds. No point wasting voyaging tokens.

Dude epoxy is obviously better in all situations, but you pay the quality. My recomendation is to use epoxy only with carbon fiber and for infusion/ vacuum parts. If you laminate manually, don't use epoxy. Vinylester is super hard resin, very good quality and it's more than enough if you are laminating sandwitch parts or some tabs. In any case NEVER mix esters with epoxies, it won't bond together. I would use vinylester in your project.

I used to learn in training that epoxy is much better, and less toxic... switching companies I there was the exact opposite opinion... styrol will dull your mind, but supposedly exits your body within 24h (studies done in the 80th🤷) epoxy contains bisphenol A which may cause cancer and is odorless as well as some stuff in the hardener making people allergic. in terms of performance and usability I got to know good results with both although resin infusion is much easier with slow and low viscosity epoxys polyester is much easier to get a fast cure to build upon and hammer out some repairs fast

I love your tests! I find them super educational. Loving the work youre doing to Uma. Great job!

As someone with zero experience in boat building this is fascinating. Thank you for sharing guys. It seems that there may be a whole bunch of marketing going on and a lot of money perhaps, perhaps being wasted, in smaller boats but I really liked the argument that that other builder had, that epoxy might indeed be stronger, but only with much larger vessels and loads? Don't know obviously, just fascinating to see the many different comments and opinions. Thank you to all.