laminating the hull

[captain red]

8) Hi, My next question is what materials do I use for this. I have read that polyester is no good, epoxy is not really waterprof, but vinylester may be the way to go? I have worked with polyester does this vinyl stuff work similar to that? what has been your experience with these materials?

Thank you, captain red

[Mike Donlin]

In my opinion I would look at how you are going to sail the boat, trailer/day sailor with a few overnight or weekend flings, epoxy would be the way to go. It is easy to work with, the odor is very pleasant compared to the other two, and unless you are going to leave this boat moored for 6 months at a time I think the waterproof issue is moot.

I think the reason poly and vinyl get mentioned at all is because when the plans where first drawn up in the early 80's these were more readily available than epoxy.

Larry at RAKA www.raka.com is a fountain of information on epoxy and can help you out with any epoxy question or problem you might encounter, he know these boats and can give specific recommendations if you want to upgrade to kevlar on the keel, etc.

I wouldn't be afraid of epoxy at all on these boats, it is so easy to work with once you get over "first batch fever"

[Barry Pyeatt]

Captain Red,

I would echo the suggestion to contact Larry at Raka or call West Systems.

Polyester resins have been formulated to work primarily with glass laminations, they really are not what we would favor for use with wood.

Vinylester resins work well for the application of the glass cloth to the wood substrate and give us a nice base for finishing.

Epoxy can be used for assembly, laminating and finishing.

You can also use the Urea/resin glue.

When they talk about not being water proof, they are talking about a boiling test. So unless you are planning on boiling your hull to cure it, I wouldn't be concerned about that.

But when it comes to bonding two pieces of wood together, as in laminating I would recommend epoxy as the first choice in these applications. It is easy to mix, apply and makes a dependable bond. With fillers it can be used for filling and fairing. But there are fairing compounds available as well.

[Guest Anonymous]

8) Hi, I guess epoxy is the way to go. I will keep my boat on a trailer when not in use. I have experienced the marina catchem and skinum billing methods once, not no more!!!!. Thats why I like these trailer sailor boats so much. I really like the lines and look of the vacationeer as well as the weekender. I like the economics of them as well. Several of the trips my wife and I want to make is to sail around the perimiter of lake michigan and sail the apostle islands in lake superior. These are just for starters.

Thank you, Captain red

[Charlie Jones]

There are boats, built using epoxy, that are currently and have been in the water full time for over 20 years or more, Epoxy may not be totally water proof, but it's the next thing to it. The water and fuel tanks I built and put into a trimaran in the very early 80s are STILL in daily use.

I certainly wouldn't worry over much about the longevity of wood/epoxy.

[Frank Hagan]

Like most other amateur boat builders, I would recommend epoxy.

HOWEVER, if you are building the Vacationer, you have to change the materials list to use epoxy. I think the Vacationer plans call for fiberglass MAT to be used on the hull. Epoxy will not work with fiberglass mat; it has to have either polyester or vinylester resin to break down the binders in it and cure correctly. If you are building the Vacationer, you have two "good" options: use vinylester with fiberglass mat, or use epoxy and have two or more layers of 6 ounce fiberglass cloth. Most builders today choose to use two layers of cloth and epoxy rather than the fiberglass mat and vinylester.

[Craig]

Don't even consider the mat Capt. Follow Frank's suggestion and use epoxy with an extra layer of cloth. Same strength with no worries and a very, very reduced amount of labor.

[MikeStevenson]

We have decades of boats which have been built using polyester resin. It works fine. The problem people run into is not using enough resin to compensate for the wood soaking some of the resin. Polyester is thinner than the other types of resin and is easily soaked up by the wood (even by foam, depending on the type). This leads to dry-out, which isn't good.

The book-learned versions of fiberglassing will tell you that a dry lay-up is x-amount stronger than a wetter one. This is true if you've done a nice, compressed job (as vaccuum bagging can achieve to some degree). All of the surplus military layups we used to find in scrapyards were like this: extremely dense layups which looked like they'd been done in a lab.

If you live in our world, you'll quickly find that dry lay-ups are not neccessarily as strong as a well wetted one. Add to this the fact that dryed out laminations on wood tend not to stick well, and you've got a nice fat urban legend: polyester doesn't work for plywood boats. Not true. Before there were epoxy fiberglassing gurus to tell us all different, we all just built boats with polyester and went about our business. There were no alternative resins. Now there are two better choices, but that does not alter the fact that polyester will still do the job if used properly.

Mike Stevenson

[capt jake]

Excellent information Mike!

The problem people run into is not using enough resin to compensate for the wood soaking some of the resin.

Fact is, if you don't wet out the epoxy well enough, the same problem will develop! One must go back over the applied area and assure that it is properly coated, before it begins to cure.

I think this is going to be true no matter what product is used.

[Guest lugsailer]

Hey Cap't, I wanted to jump in on the resin discussion because I build and sail boats with composite wood/resin hulls. Marks Handbook for Mechanical Engineers states that polyester resin sticks to wood with an 8 out of 10 adhesion; conversely it adheres to metal with a 2!!! out of 10. Don't most people associate polyester resin with metal? I have used polyester resin and painted over it with tinted epoxy and later drove nails through it to attach a wale with no problems then or later. Hope this helps. I always go to the Engineers handbook and sift everything else I hear.

[Guest]

IN REGARD TO THE BOARD AND DESIGNER, I RESPECTFULLY PRESENT THIS COMMENT:

I would like to add one opinionated thought to the discussion, if I may here. I think sometimes it just depends if a person is "COATING" or "LAMINATING" for structual intergrity. As I study more of the Stevenson design, and as I have gone about my merry ways on a lot of cold mould construction building, plans differ that give up beef materials to alternative methods of allowing glass to be structual, and the wood is just the mould.

In doing this, I have found that you will need to have more or better type glass than just finishing cloth, with just the polyester resin, or fatigue will create a failure in wood-glass construction, therfore creating the myth for many people that polyester is no good.

Please accept this thought, as an underlying factor, for what you paid for it, nothing. But I have seen this as the one single factor to the "JUNK POLYESTER" in wooden boat constrution problem. THANK YOU. Now back to your regular program.

[Robert Cox]

If you spend much time talking to Larry at Raka, he will tell you to put on a pre-coat of epoxy before laying the fiberglass. I've seen dry lay-ups of fiberglass using epoxy as well as the polyester resin.

I was using the 5 oz. cloth and Larry suggested pre-coating the plywood and letting that dry before applying and wetting out the fiberglass. I would suggest doing this before applying fiberglass wether using polyester or epoxy. This way you know that the wood has soaked up what it can and the resin used for wetting out the fiberglass is not being soaked into the wood.

Oh, and I used two layers of 5 oz. cloth on the hull of my Vacationer.

Bob

[ken connors]

Bob, regarding your 5 oz cloth, what width did you order and how did you lay it out. did you use unseamed sheets for each side of the bottom?

[Frank Hagan]

IN REGARD TO THE BOARD AND DESIGNER' date=' I RESPECTFULLY PRESENT THIS COMMENT:

I would like to add one opinionated thought to the discussion, if I may here. I think sometimes it just depends if a person is "COATING" or "LAMINATING" for structual intergrity. As I study more of the Stevenson design, and as I have gone about my merry ways on a lot of cold mould construction building, plans differ that give up beef materials to alternative methods of allowing glass to be structual, and the wood is just the mould.

In doing this, I have found that you will need to have more or better type glass than just finishing cloth, with just the polyester resin, or fatigue will create a failure in wood-glass construction, therfore creating the myth for many people that polyester is no good.

Please accept this thought, as an underlying factor, for what you paid for it, nothing. But I have seen this as the one single factor to the "JUNK POLYESTER" in wooden boat constrution problem. THANK YOU. Now back to your regular program.[/quote']

Hey, interesting theory, Oyster. It would explain why the Stevensons have had good luck, as the Weekender could be built and sailed without any resin on it (it is structurally sound with just the plywood). Now that epoxy and cloth has gotten so expensive, it might make sense for someone to build a Weekender with one of the cheaper grades of okume ply, and just fillet the seams and paint it.

Also interesting that polyester, as an engineering material, does stick to wood (I imagine vinylester and epoxy are up there at a 10 on that scale, but hey, it still at least sticks to it!

[Robert Cox]

Ken, we use the 50 inch cloth.

The Keel was done with one piece on each side overlapping the bottom of the keel. This piece also went over the keel fillet at the bottom.

The bottom was done with one piece on each side of the keel. This piece overlapped the keel piece at the fillet. It over lapped the sides by four inches. It over lapped the transom by four inches also.

The side panel was one piece on each side that over lapped the bottom by four inches and the transom by four.

The transom was obviously done with one piece and over lapped the sides and bottom by four inches.

The only seams in the glass was at the chines, stem, keel and transom edges.

Of course we then layed another layer of glass on everything but the keel. The over laps on the second layers was only two inches to stagger the seams. The best part of this was that the chines and transom bottom now have a total of 4 layers protecting them. If I had it to do over I would have made the over laps 2 inches on the first layer and 4 inches on the second. Would have been easier to fair out.

We used 6 gal. of epoxy and about 60 yards of fiberglass to cover the whole boat.

Bob

[ken connors]

thanks for the informative reply, Bob. you just doubled my hull finishing budget! :cry: i like the idea of the four layers at the chines, tho.

[Guest]

Its only money folks.

How do you spell BOAT? B O A T.

BringOnAnotherThousand

[capt jake]

Oyster, I always thought it was a whole in the water you threw money into; Ooops, I guess that would be my house (only throwing money into a dry hole!) . Har har!

[Guest]

The difference Capt. is most women approve of spending unlimited amounts of money on the "DRY HOLE"

[capt jake]

Only 'certain' un-limited spending! that is why I am re-siding the house!! (in preparation for the re-flooring!!). :) HA! ha ha, what am I doing?? hte 'ha' is on me! :0 ha ha hr ho oh oh know!