encapsulation and stitch and glue

Hello everyone, I plan to build a Simmons Sea Skiff (18' outboard) stitch and glue, but I have read conflicting advice on whether to epoxy the whole boat inside and out. Samuel Devlin's book, "How to Build Any Boat the Stitch and Glue Way," insists that everything should be epoxied, inside and out, in order to keep out moisture. Dave Carnell, who is apparently the authority on the Sea Skiff, says that the epoxy will not keep water out and just adds extra weight and expense.<br /> Devlin's reasoning seems sound, but Carnell's permits a lot less work. So, my question is whether to encapsulate the boat. <br /> Also, does anyone know a good method for stitching lapped planks? Or are they not stitched, but temporarily clamped, nailed, or screwed?

Re: encapsulation and stitch and glue

The Oct 2003 issue of Popular Mechanics profiles a Boat in a Kit. It is a 15 ft Chester Yawl using stitched lapstrake construction. You may be able to see it at:<br /><br />www.clcboats.com<br /><br />It is a "stitched" boat. As to your other questions??????????????

Re: encapsulation and stitch and glue

As regards epoxy, what you using for plywood? In constant exposure in the water or weather, fir ply will check over time unless it is glassed over with 6oz glass and epoxy. Simply encapsulating it in a couple of coats of epoxy will not stop fir ply from checking though it will retard it. Boats that are stored undercover, etc will last much longer. I have four sheets 16' marine ply under my 'north forty' cover and they've been there for seven years and still look good..except dusty. That's in the PacNW. Someday I'm gonna build a boat of it. Okume or mahogany or other plys will last much better but are more expensive initially. Contact Gougeon Bros or MAS or System3 or some other epoxy folks and they will give you free advice on this topic. Or buy their book and read up in advance. It's cheap insurance to know more about this before you spend money.... Often when building a boat it's best to follow the directions. I've met and talked with Sam Devlin in years gone by and he has decades now of experience.

Re: encapsulation and stitch and glue

i'd did a stitch & glue 16 footer... what i read,, what the instructions said,, an what i did was total encapsulation.. two coats on everthin' an more on the edges.. even on surfaces that i knew were EVENTUALLY ( i say EVENTUALLY cause it's a long time commin' ) goin' to be glassed clothed over... i did not think it was a waste of material, time or money... <br /><br />it protected the wood as i was buildin' an have to have a barrier coat on,,anyway even before glassin' as to stop 'wickin' of the epoxy from the applied cloth..<br /><br />one hint.. get/find/buy a 1 to 1 epoxy... 1 to 1 has very little wax ( amine blush ) an DOES NOT need sandin' bettween coats an/or cured surfaces... <br /> plus it's just easier an better to mix EVEN amounts... WORTH IT'S WIEGHT IN GOLD ..IF'N JUST FOR THAT..!!<br /><br />1 to 1 is hard to find,, tho... but clark craft has it an a good price...<br /><br />DAVE CARNELL is the man... no dought...<br />what he said is,, nothin' can keep water truly out of wood ... but by phenomeon,, epoxy keeps out rot...<br /><br />that's good enuff... no rot is a good thing...<br /><br />OLD SAILOR ,, shoots straight...he knows what he's talkin' about... <br /><br />but don't be afraid of good dry a/b doug fir or doug fir marine ply... few good coats an the un-glassed / no traffic 'flip side' of the ply ,,, shouldn't check at all... <br /><br />just don't use that a/c fir home center crap...

Re: encapsulation and stitch and glue

Thanks to you all for your replies. I'll look up the Chester Yawl, I plan to use marine plywood, and I think I will encapsulate. What about the wire stitches? Do I have to heat them up and pull them out completely, or can I get away with clipping or filing them?

Re: encapsulation and stitch and glue

use what gauge the instructions call for..<br /> <br />it's 14 or 12 ga. soild copper..<br /><br />on the inside/interior of boat ,,you hammer/tap the loop (of-the-stich ) flat.. <br />(the twist-of-the-wire is on the outside of hull ..) <br /><br />you have to mix up putty,,i.e. epoxy & fillers.. apply putty over joint to make a 'fillet'/swaill/gully as per to lay down epoxy wetted biaxial cloth.. <br /><br />the putty goes rite on/over the copper wire to be never seen again.. <br /><br />on the outside,,, 'the twist' is cut off flush an nail set into wood...putty is then applied to joint an biaxialed,, also..

Re: encapsulation and stitch and glue

You can look at the history of plywood boats and get a pretty good idea on what to do. <br /><br />Back in the 50s/early 60s most of the 8'-18' trailer boat type skiffs, rowboats, dinks, etc. were made of exterior or marine ply. Many were fiberglassed on the outside and painted with enamel inside and outside. Cheaply built ply boats lasted 10-15 or more yrs if you didn't let water sit inside or leave them sitting on the ground...termites happened where I lived. It only takes a year or so of negelect to trash a ply boat too.<br /><br />Ply boats built without any glassing and just painted lasted about the same time with the same care. Painting once a year helped keep the wood sealed. Fiberglassing was done to keep them from leaking more than any other reason I ever heard of. Checking may be a problem but proper painting methods took care of that back then (as in pre glass days). Those methods were basically to put a 1/2 dozen or more coats of highly (50%)thinned (with mineral spirits) oil based enamel to fill the grain and follow up with at least 2 final coats. It didn't check...ever. Sealing is what made them last.<br /><br />About the full coating of epoxy...I would do it. It's the best technology going for wood and will help keep it dry. Epoxy is a proven h20 barrier coat. I suppose (if you dig deep)the main objection to coating inside is focused on not being able to keep it from being dinged/scratched or compromised in a way to let water in under it. Water gets trapped and no way to dry, then rot is likely. That has always been the plague of glassing wood boats. Relax and don't get hyped up thinking your boat is going to self destruct if it is coated or not. Get a vented cover and keep it dry...it will be around long time.<br /><br />Bill P.

Re: encapsulation and stitch and glue

Crab bait, thanks for your instructions. You have me almost totally convinced to ignore Devlin's imperative regarding completely removing the wire stitch. I have read other how-to's that jibe with your instructions.<br /> BillP, your words make a lot of sense. I have a little experience building and maintaining plywood boats, so I know the value of regular sanding and painting. The only time I have worked with fiberglass is when I have clothed over my plywood prams after they have begun to leak, and that doesn't last very long. A couple of years later I have to order another kit and build a new pram. I still can't tell whether you suggest epoxy for the inside because its a better sealer than paint, or if there is some residual benefit to paint or varnish because it is easier to fix minor scrapes and dings. Maybe it isn't easier? Is that why come out on the side of epoxy inside and out? Or is the epoxy comparitively difficult to repare but harder to ding?

Re: encapsulation and stitch and glue

My opinion is YES I would go with epoxy inside and out. It just needs 100% of the wood coated (no pinholes, holidays, etc.)so water can't get under it. My preference would be to do several thinned coats (10-15%)until the grain is 100% filled. Then a final coat with 1-2 coats of straight mix. It is the toughest and most waterproof coating you can do without glass fibers. Do some test samples of your materials on plywood and hit them with a hammer until destruction...it will open your eyes on how tough it is. <br /><br />You can add pigment to the resin for color but painting every couple of years will make sure it stays sealed. If you leave it clear you can see water intrusion before it gets out of hand...but the resin needs to be protected from ultraviolet damage. I've always painted over resins so don't know if they have epoxy or additives for 100% ultralight protection like they do on polyester.<br /><br />Just like all wood boats, make sure all the wood frames, supports, stringers, etc. have limber holes or bevels to let water drain. Your are glassing the stitch on both sides so take extra care on the tape edges so they can't get snagged.<br />Epoxy is easy to repair.

Re: encapsulation and stitch and glue

the epoxy encapsulation is the way to go.. <br />just make sure/an take great pains in keepin' your wood dry.. over 12% moisture an wood can rot from the inside..<br /><br />the encapsulation also keeps the finish i.e. paint or clear uv protectin' varnish from<br />peelin'poppin' & crackin' as per just a painted surface.. as per water gets underneath an forces this to happen..<br /> <br />don't happen with epoxy..<br /><br />the only time you'll need to RE-paint is if it fades in time or you just want to..<br /><br />it is not reccommended by any epoxy manufacture to 'thin' down epoxy...<br /><br />finally,, epoxy is a cintch to repair .. the epoxy i told about,, the only kind i use,, is hard but soft enuff that it's NEVER scratched off .. it just indents ( goes-with-the-flow of the accident ) an has never been compromised...<br /><br />lord knows ther's many many 'indents' in the 'ole girl..

Re: encapsulation and stitch and glue

Final question (I swear): Do I have to pull out the stitches or not?

Re: encapsulation and stitch and glue

i already answered that...

Re: encapsulation and stitch and glue

Crabbait: <br /><br />Don't take this as confrontational, ok? Mfgs don't recommend thinning polyester with acetone either but everyone does it with relatively good success. Even big buck boat mfgs, such as SeaRay, used it and still may. Same as thinning epoxy with acetone...lots of history out there that shows it works successfully in certain applications.<br /><br />I've been thinning epoxy with acetone and denatured alcohol since the mid 1970s and never seen, had or heard of a problem with it. This has been with different brands and ratios...including WEST brand. Some of the big projects I've done ("wested" 32' & 42' sailboats)didn't show any difference 10+ yrs later. <br /><br />Here's what my own crude testing shows...the thick coating will peel off ply with the surface of the wood attached to it...plenty strong for bonding but not deep into the grain for h2o protection if the surface gets dinged. When thinned first, it peels deeper and closer to the first glue line and is harder to pull off. <br /><br />As a side note, every thickener I tested, except glass fibers, really kills bonding properties of epoxy compared to thinning with acetone. Thickened epoxy (to buttery consistancy)doesn't normally pull a lot of wood grain off with it. 99% of the stitch and glue boats use a lot of thickeners. This hasn't been a problem because epoxy is major overkill in the strength department anyway.

Re: encapsulation and stitch and glue

Another vote for epoxying the whole boat. I'm building a S&G too and researched this question extensively before starting. Check out web page for some real good info and designs of S&G boats<br /><br />Good Luck