Whats this rumor about epoxy might not be so great at encapsulation after all

Thanks Mark- I do dislike the bickering that can occur.
In this case PAR stands as a senior member whose experience in this area exceeds that of many, including myself.
I take no offense as it was discussed (decided?) some time ago that some moderation of the forums by senior members is appropriate to help form the discussions here.
Outside of that- I am trying to not enter these fights for the last word on any given topic.
We all have lots of experience and this site serves as fine way to throw around ideals.

 

I'll be building a double diagonal planked or cold molded structure. But I want the stained wood of the topsides and deck detailing done with an alkali based stain and finished in tongue oil. I've used that combo countless times and I can make it shine like no tomorrow. I also like that you can just mop more oil on right over the old stuff and it looks like new.

I'm working on renting a space now, just waiting to hear back from the folks involved. Its a huge space, part of the local artists coop scene, overhead crane, huge doors and cheap cheap cheap. large locking room for the tools. Fingers crossed

I'd like to start with something like this



I'd use a bit of paint on the hull but you get the idea



old school enclosed cloth canopy tho, something light and saloon car looking
it would live indoors on a trailer

I'v got some prints for it and was just wondering about if anything had changed in the epoxy world since I last brought it up.

 

When I observe deterioration in a professionally designed boat its always water intrusion from poorly executed joints, improperly bedded hardware, incorrect machinery installation , standing water in the bilge or physical abuse. . With attention to detail , good craftsmanship, and by following the designers building notes to the letter, you will have no problems with either cold molded or triple planked. I was just on a epoxy cold molded sailing yacht built in Germany 14 years ago. The bright finished interior hull planking in the bilge was perfect.... bilges dry, no sign of water intrusion, no sign of deteriorantion . Very good craftmanship.

 

Deal is I'll be building some old runabout design just to get my feet wet and its pretty much a complete deviation from the original plan to use epoxy at all. Back when the one pictured was designed I'm not even sure Resoursinal had been invented yet. I'll do something like stringers over bulkheads on a chine form hull with double diagonal or cold molded. Rather than the filler blocks over bent frames that Hand design calls for. Basically I'm not even remotely following the original plan but using modern cold mold or double diagonal technique to build a traditional design. The original Hand plans calls for bent toothpicks under countless filler blocks to develop the hull shape under a planked hull. Not happening, cold molded hulls are just stronger, lighter and drier. Attention to detail, joinery, mechanical installation, proper bedding of fasteners and all that, definitely. But following those old turn of the century prints, no way. My theory is we've come a long way and as long as I don't mix and match techniques I' should be fine on the hull build.

and ya I got a NA to check what I have in mind so no worries.

 

I don't think Bntii misunderstood my comments, though it would seem some might have hoped he did. In fact he's right, in the follow up post in regard to material choices. "You can pay me now, or pay me later . . ." which we both understand and his assessment of how the damage occurred.

In fact, the epoxy failure Bntii talks about (6/4 mahogany plank) is a precise example of improper application. The internal stresses that can set up inside wood, have to be contained. They can be if you encapsulate and bond with pieces no thicker then 1". I have a list of species that fit this old West System recommendation and those that require less, such as the oaks and teak for example, where 3/4" is pushing the boundary, before you can expect environmental changes to overwhelm the encapsulation and/or bond. So, it wasn't the "brittle glue" as Bntii mentioned in his post, but in fact improper bonding. Had the 6/4's piece been two 3/4" pieces bonded to each other, then to the house side, it's likely they'd still be in good shape, though he does mention fastener holes, which can be a problem for any encapsulation project. In the end, he still figured it out with

clearly reasonable deduction and observation.

Casein glues aren't waterproof Wardd. They actually suck pretty bad compared to modern adhesives. Resorcinol is a whole different beast and is waterproof. It was the defacto glue before epoxy came along. I still use it and it's common in many things. Generally speaking it requires perfectly fitted joints and needs lots of clamping pressure and ideal temperatures during the cure or you'll have issues. It can turn to power as it ages, but if the joints were well mashed together, usually not a problem. The physical attributes of this adhesive are well documented.

It figures, Fanie drops in as the solvent sniffing, polyester eating, solvent sniffing second on the epoxy sucks band wagon. I'm going to have to try some time in a small room with an open 55 gallon drum of styrene, just to see, what all the fuss is about.

Boston knows that mixing build methods is fraught with issues. It's a bit like coming out and saying you're gay. Once you're out, it's out and you're pretty much married to it. The same is true of epoxy in an old design. Once you've decided on epoxy, there's no turning back, you're married to it and have to go all the way. Now that everyone is having a mental image of Boston having sex with a big hairy guy named Bubba, I'll let it go.

When looking into epoxy life spans, you should look at areas where epoxy has made a huge impact, such as concrete finishing and fastener holding. This industry (as well as many others) have conducted many tests and durability studies. Also the military's applications are another potential source. Naturally, the major formulators also have documentation on long term testing.

The short of it all is concrete road beds, fastened to bridge truss systems, with epoxy adhered anchors, are expected to survive their 50 year replacement schedule with a healthy safety margin. Given a measly 2:1 safety margin, a century's worth of reliable service isn't such a bad thing to expect.

 

That's a beautiful boat but is it really what you want? I thought you were looking for more of a live-aboard.

 

I totally agree with that assessment Bntii, I too would have bedded it, if for no other reason then it would have to come off some day, to be refinished or repaired. A nice squishy bed of polyurethane could have solved this problem easily.

 

This is one of the issues that I try to get right, and struggle with- to bed or bond....

Rules of thumb would be nice as it is too late when the job fails and you see a problem with a clients boat at some point down the road.
I am developing good judgment & long gone are the days when epoxy seemed like a universal answer.

 

Why was I expecting nothing less than the abuse I've grown so accustomed to ;-). Hoyt Im going to build something to go play on until I can get the retirement build under control, besides I'll learn a lot in the process which will make for a better build in the end. That and it gives you guys something to ***** about when I start getting silly with the joinery.

 

No offense B, but why build?

I just picked up a particularly nice "Blue water" D) sailboat for much less than the rig would cost on a new build.

She is ready to go- add beer and beans and some nice lass.

 

Don't build in Colorado. Big trouble on the way.

 

"beer and beans" - Anything more? Well, the occasional nice lass but beer and beans covers the essentials!

Nice work, Hoyt! "Viene la tormenta" - http://www.youtube.com/watch?v=5X_nnGuOdKA&feature=player_embedded

 

Just heard of minus 43 in MN Hoyt

If you have any pull - do you mind if we don't get the ice age started just yet?

 

brrrrr!

 

No worries B but building my own is half the fun. If I cant find just the right boat for just the right price then I'm going to build it. I'm looking for some wreck I can salvage the mechanical from but I've done enough remodeling to know that sometimes its just easier to start from scratch rather than be constantly replacing a piece here and a piece there. That way I'll have a nice shiny new should last for a while before major repairs are needed hull without all that fighting of some old rickety POS every time I pull into port.