Titebond III testing

New boat builder

I'm new here, this is my first post. I have over 20 years experience as a Tool & Die maker, Machinist, CNC programmer/Operator. I also have Auto CAD and CAD/CAM experience. I have been building wood projects for the last year. I perform at living history events as a 1720's Pirate. I have decided to build a 18' Sailing Dory with Clark Craft plans to use at some of these events. This will be my first boat. I chose the Dory so five or six of us can use it at a time, its stability and ease of construction. It will be primarily oar powered with the mast (s) added later. 1/2" side and a 3/4" bottom.

My questions: Will this glue stand up to the stresses the Plywood would exert after being screwed into place on this project?

What would be a better choice?

Has anyone here used Clark Craft plans?

I had planned to use Titebond III as the only glue to construct this boat. I'm having second thoughts now after reading this post. I was going to use Stainless steel screws to hold everything together until the glue set. I was going to apply a layer of fiberglass cloth and two coats of epoxy to the exterior hull. Inside and out with epoxy paint.

The boat would be used maybe a dozen times a year in bays and harbors in coastal SC. It will be kept in a shed when not in use.

I came here BEFORE I started to do research and get advice to prevent wasting materials and money.

Thanks in advance for any help.

 

If they are identical that indicates creep - which would vary between samples - is not a factor. I checked my calculations and found an error; springback is 1/(n^2-1) not 1/n^2 as I had assumed. Also the spreadsheet has an approximation that assumes a shallow arch, not true in this case, so my calculated springback is incorrect.

So far, I have found Titebond III an excellent choice for plywood construction. However, the manufacturers do not recommend it for below the waterline. I use it in most places, but change to epoxy for joints exposed to the water.

Appropriate construction is determined by intended usage, of course. I think the above is OK on a boat that will not be left in the water for extended periods like yours. For any boat that would live at a mooring or marina I'd use epoxy up to the sheerline.

I assume from the use of S/S screws you intend to leave them in place. I think that is a good insurance policy for external joints below the waterline that can be subjected to concentrated loads. However, for glass-reinforced joints it is probably overkill.

 

Epoxy doesn't stick very well to the TiteBond products, so keep the spills and drips to a bare minimum, so the surfaces aren't contaminated.

TiteBond III isn't a structural adhesive and just barely passes the type I WBP tests. This means use with caution, particularly in conjunction with epoxy sheathings and underwater applications or heavy strain items.

TiteBond III is intended to hold furniture and cabinets together, not highly stressed structural elements. This is especially true if the parts will be "cycled" in loading or wet/dry environments. There are many uses for it on a boat, but it's not a good adhesive for several applications in the marine climate.

It's likely your dory could be built entirely without adhesives, in a traditional fashion. On the other hand you could make it truly watertight with epoxy on the laps and rabbits only. Sheathing is an option, but with your planned usage schedule, you could live without this bother, effort or expense.

 

I don't see resorcinol glue being recommended much in these posts. I have used it for years with satisfactory results. If it has fallen out of favor to the advantage of epoxy, I would be grateful to know why. Would anybody have any knowledge about this?

 

The plans call for plywood on frame construction. Frame built upside down. PW screwed and glued onto frame. Silicon bronze or SS screws to attach PW will be left in. Fiberglass cloth and epoxy over each PW joint then fiberglass cloth and 2 coats of epoxy over entire hull and then paint. 6 inch wide piece of PW on inside of hull glued inside and screwed from outside at each PW joint. Frames are 3 piece, notched for keelson, lap jointed, screwed & glued. Keelson lag bolted to frames and glued.

I'm not building an heirloom, if it'll float for 5 or 6 years I'll be thrilled. I plan on using construction grade materials from Lowes. This is why I was going to use epoxy paint inside and out. If it's firewood in a few years that will not break my heart. I just don't want it to collapse and sink with five or six Pirates on board and cause the loss of expensive swords and other gear second time out.

I was trying to get away from mixing, but since the PW goes on one small piece at a time, I can mix what I need and then repeat.

If using a different glue will increase its life span, so be it. I just don't want to spend $600 on wood and $300 on glue.

Thanks for the quick responce.

 

Clark Craft sells and recommends GL 10 super epoxy glue for the entire build. It's $27 per quart 2 part equal mix.

Mfg. details:
------------------------------------------------------------------------
GL-10 equal mix glue type adhesive is the best of its kind on the market today. We have had our GL-10 epoxy glue formu-lated to a thick yet spreadable consistancy so that it will easily stay in place when spread along a vertical surface. GL-10 has an approximate 1 1/2 hours pot life at 70° which is ample time for most projects. Under high stress condi-tions such as an impact, we find that the GL-10 glue line will hold fast and the wood fiber parts either side of the glue line will generally shatter, the mark of an excellent glue. Bonds wood, fiberglass, concrete, glass and most metals, is transparent to amber in color.

Equal mix
No shrinkage
Cures at 35°
Cures on moist wood
Over night cure
Contact pressure
Gap filling
Once cured can be drilled, tapped, machined or sanded.
---------------------------------------------------------------------
Maybe I should use this? $74 a Gallon I think. Sounds like good stuff. If I use it throughout the boat it should last 8 or 10 years. That would be fine.

What say ye all? Thank ye in advance.

 

My advice: Don't use construction grade plywood. It won't be that much more for good marine grade plywood, which will leave you much happier with the result. Others here will probably explain better than I, but hollows in construction grade product will very early demonstrate why you were wrong to use it.

 

Point taken, thanks. I'll have to find a suppler in my area. I've read about the grades of PW over the last few weeks.

I can buy a nice Dory for around $3,000. I was hoping to build one for under $1,000. So you can see my reasons for using Lowes. LoL

 

Even a less than "nice" dory might be worth you looking into if you have skills at fixing things. You could save some considerable money if you are careful and the dory isn't too less than "nice".

 

if your going to build it in front of folks Ild go traditional all the way
even maybe wear the triditional garb while you do it and use traditional hand tools
hell you could use pine tar and tree nails and probably get away with a reasonably water tight build
I never was much for plywood but if you have a local mill around somewhere you can get some nice planks cheep and go from there
what the hell you got six pirates anyway
you could keep a couple of em out of trouble adzing and a let em earn there grog

 

Oh crap no, I'm not going to build it in front of witnesses! LoL

I just wanted a boat where 5 or 6 of us could row around and shoot our weapons and participate in the festivities at the wooden boat shows we attend some times.

It would be built here, hoping to get as cheap as possible, hence construction grade PW. But since I have to "glass" and epoxy the hull to do that, I could use Marine PW and just "glass" and epoxy the seams and paint it for the same price and have a better boat. Hmm now I'm stumped.

 

well then sinking could be part of the act
dont be a such a wimp
I never heard of a pirate scared of getting his sword wet before
you one of them "funny" pirates there swabby?

 

LoL Nope, just we all carry "real" swords, spring steel because we also do fighting demonstrations and we carry real firearms. Swords at $300-$500 each and flintlocks at $450- $600 each would be a big loss if it all went to Davy Jones locker! LoL

We could just leave all the expensive gear ashore I guess.

 

ya I used to work at the Ren Fair for a few summers long ago
I got all the stuff as well
thats why I was razzing you
hell that hand made leather mug I got ( #28 from some famous mug maker actually ) is worth about $250 and those swords
you got a bargan at a few hundred bucks
flint lock pistol eh
hmmmm
I might have to have one of those
although they got harbor divers you know
so your still lacking any real excuses swab

I say get brave and build it right on the dock
hand tools only
the crowd will love it
if you screw something up
you can argue and chase each other round at sword-point just like the Renaissance fair

best
B

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someone wanted to see what I was doing with the arches
raised panels are not cut yet but I wanted to dry fit the styles and rails before I traced em

 

Pirate L: If it's ply over lumber frame construction it will be difficult to get the zero gap joints that Titebond III insists on, so epoxy is likely your best bet.

Much of the construction ply I've seen recently is shockingly bad quality. If you can't spring for marine ply, look at baltic birch py. Birch is not the ideal choice but if you are going to moor it indoors it won't get a chance to rot and it's strong. A bit heavier though.

However, if you're not in a hurry, shop around. I have bought marine ply well below the usual price on several occasions, one had paint quality surface veneers but was structurally OK, another lot had been water-stained, just the corners but still half-price. I've built up enough stock for a few years of boat building.

Boston: darn, I thought you were going to keep those arches and measure the creep for years. Where's your sense of scientific enquiry?