Laminating wood for a bowsprit

[Bowdrie]

I stand with what I said.
From the kid building a rowboat in a barn to a team of pros building a mega-million yacht, using many variations of plywood/strip planking, and cold molding, the use of epoxy products for various forms of gluing/lamination has been going on for decades.
That's real-world experience with many species of wood in all types of climates with all types of techniques.
And lots of successful teak decking has been used and we all know how hot teak decks can get.
These boats are not getting weaker/failing from temperature variations, they're being used/sailed everywhere you can think of.
The scientists in a climate controlled clean room with their sophisticated tools can produce all kinds of mathematical data points, no denying that.
But hundreds of guys working in various places on various projects with conditions all over the map, and sharing info, will have a pretty good idea of what goes on in the shop and the results the average worker can expect as opposed to lab results.
Yes, as I've said several times, resorcinol can be a great product for many uses, but for an amateur to laminate up a big timber without a goodly investment in tools/equipment is a tall order.
An 8"x8"x13' timber is not the same as a scarf on 3" wide plank that's an inch thick, or a 1" rabbet joint on a mast.

[Bowdrie]

Ok, part of the job in doing things on boats or helping others, is to figure out how to turn a mountain into a molehill.
So, with that in mind, here's another option that the OP might consider.
Instead of trying to produce a good quality lamination, it might work out to just buy one already made.
In most anyplace it shouldn't be that difficult to get a "Glulam" beam or a section of one.
I've been to a factory that produces these, quite impressive.
All kinds of options can be specified as to woods/finish.
https://www.bc.com/ewp/Boise-Glulam/

[deltaten]

Jules, of "Emerald Steel" u-toob built a new sprit while aboard. Locally sourced hem-fir whatever, laminated with epoxy and shaped to need. All around the Pacific since. Hasn't failed yet and probably won't.
While I can appreciate the chemists and product engineers take on doing things, I'd much prefer to listen to a fella that has actually done it and been successful.

[CharmCityBoater]

I think true DIY'ers, like myself, do not have time to dig deep into the science behind a lot of the epoxies / glues and the lab testing results. As pointed out above I base a lot of my decisions about what is working in the real world. I know West Systems epoxy and Smith's Oak & Teak glue have been suggested and used by others with a similar skill set as mine. They have been successful and I have not heard of any problems they have had since the work has been done.

I was basing a lot of my approach on this video: https://youtu.be/OAwWTmDH7k4?si=vGTkouVQ49sRqQYF

Any compelling reason why this was not done properly? Seems like a solid, well thought out job to me. He used Smith's Oak & Teak glue.

Thanks

Phil

[CharmCityBoater]

One other point... I would love to find a solid piece of wood, so I do not have to laminate one up. With that said I have called around many places. No one caries lumber that large. For those suggesting I use a single piece of lumber where do you suggest I get quality, rot resistant, wood, suitable for a bowsprit that large? If it exists, I cannot find it.

Thanks

[Bowdrie]

Originally Posted by CharmCityBoater

For those suggesting I use a single piece of lumber where do you suggest I get quality, rot resistant, wood, suitable for a bowsprit that large?

Haha, since I'm probably the only one who suggested a single piece, that question is probably directed to me.
Up here in the PNW you wouldn't generally go to the corner lumberyard either, although the real commercial yards where the contractors go would have something like a 10x10x 16Ft., but it would be of Douglas Fir.
In actuality, Douglas Fir, (good stuff with tight grain,) has been used for bowsprits for at least a couple hundred years, but you're not likely to find that kind of stock where you are.
Anyway, you scout around and get hold of the independent sawyers who are in the more rural areas.
The guys who get their logs from those who fell trees for property owners and do custom cutting.
Really, a piece of wood about 8 1/2 square by 13>14 Ft. is not a huge timber, a "heart cut" or "center cut" is the best.
As I mentioned before, Georgia Heart Pine or Southern Yellow Pine are two good choices, and I'm sure there are others.
Don't let the word "Pine" scare you, those woods are definitely a world removed from the "pine" the big-box stores sell for putting-up shelves in a cabinet.
Oh, I watched that video, they did great, nothing wrong with the way they did it or the materials/products they used.
Yeah, I've been a little "put-off" about Resorcinol, mainly because of the limitations it imposes on you for temp/moisture content, and most of all the pressure needed.
If you do a simple Google search for "Resorcinol glue clamping pressure" you'll get more stuff than you can ever read, and a lot of stuff from the WoodenBoat forum.
The absolute minimum pressure listed was 50psi., and that's for clean smooth well fitted stock.
Your planks at 8-1/2"x 13Ft have ~1,326 square inches.
Getting 50lbs on each of those square inches takes a LOT of clamps and pads.
That's why I said you'd be looking at upwards of $1,000 just for clamps.
And you could only do one plank layer at a time.

[CharmCityBoater]

Bowdrie,

What a fantastic reply. I very much appreciate your contribution to assisting me. I’ve been calling the exotic hardwoods places. I am going to try just what you said. I do remember Leo of the Tally Ho project getting some bigger lumber from either South Carolina or Georgia. I’ll see if I can go back and find out where. Douglass fir would be my choose but I’ll look into what you suggested.

Thanks again!!

[OutOfControl]

https://www.youtube.com/watch?v=aLCtq-P1dLA

Iron City, GA
About 250 miles west of St Marys, GA
Let me know if you need a translator.

[CharmCityBoater]

Best video ever!! I am definitely going to give these guys a call. Thank you.

[AKA-None]

Originally Posted by CharmCityBoater

One other point... I would love to find a solid piece of wood, so I do not have to laminate one up. With that said I have called around many places. No one caries lumber that large. For those suggesting I use a single piece of lumber where do you suggest I get quality, rot resistant, wood, suitable for a bowsprit that large? If it exists, I cannot find it.



Thanks

Have you tried looking at / for sawmills

Having a log home I’ve used a local sawmill to make beams for the house

[Sailorichiban]

Hello All,
I have both built with wood and aluminum.
The only additional tool I use for aluminum is a small wire feed TIG machine.
Carbide edged and high quality steel tools , the same ones I use for wood , work well with aluminum.
Making up a laminated beam is a time consuming process. Then fashioning it into a bowsprit is the same as a solid timber.
Wood has a lot of problems; warping, rotting (probably the most common cause to replace a bowsprit) and generally deteriorating especially if NOT READILY ACCESSIBLE FOR CONSTANT REFINISHING as is usually the case with bowsprits.
Any shape can be built with aluminum . Painting with an aluminum based finish is recommended to produce a very durable component in the marine environment.
A wide range of shapes in various thickness are readily available, Angles , rounds , different extrusions ( like mouldings in wood), diamond plates and flat stocks .
Usually aluminum can be bent, depending on the shape, hollow tubing either round or rectangular is the most difficult to bend. Drilling and tapping are very easily done. Grain is not much of a consideration.
High quality wood and aluminum construction are not so different in cost in my experience. Aluminum is my preference by far.
Best regards to all

[malbert73]

Originally Posted by Bowdrie

So, you plan to scarf short pieces to get the length and then laminate your longer pieces together to get the thickness you need?
If so, you'll need to fashion some kind of jig that uses a router to cut the slopes on each part unless you're quite skilled with hand tools.
Getting scarfs to lie flat and true/inline across 8+ inches is not a quick job.
Once you get the 13' planks made-up you'll need at least 3 clamps per foot of length and a row down each side.
Figure on needing ~60>70 clamps minimum, you'll only be able to glue one, maybe 2 surfaces at a time, and each layer will require larger clamp openings.
If you can't figure out some "backyard" method and have to spend $$ for clamps that will open 8>10 inches, you're going to be looking at $700 to $1K just for the clamps, and you still need a gluing bench that's "tightwire" flat.
There's a reason that spar builders that use Resorcinol have a few hundred clamps.
I see that you are in Georgia?
Can it be that hard to find a nice chunk of Georgia Heart Pine?
Center cut if possible, and for less money than the clamps will cost and just shape it down.
The Ga. heart pine will make a better bowsprit than trying to laminate a bunch of Sapele.
Sapele is used by Martin to make nice guitars though.

Do you need clamps or could you just use thin long bolts with large washers or plates that you then remove and fill the holes?

[Bowdrie]

Originally Posted by malbert73

Do you need clamps or could you just use thin long bolts with large washers or plates that you then remove and fill the holes?

You might use heavy oak cleats that extend beyond the wood being glued.
Drill holes in the ends of the cleats for lengths of all-thread, the all-thread being perhaps 1/2 >5/8ths, you've got to be able to really torque on the nuts.
The cleats try to bend on the overhang and lift-up in the center, so they need to be quite heavy, a 1x2 won't cut-it, some fussing around is required.
But it can work, (just throwing some numbers out,) you'll need maybe ~80Ft of oak to make 40+ clamps and each clamp will need maybe 2Ft of all-thread.
Drilling a bunch of holes for "thin" bolts will not give adequate and spread-out clamping force.
The backyard worker can't glue-up multiple layers all at once with Resorcinol, the clamping pressure required would be in the range of the giant hydraulic presses they use to make a "Glulam" beam.
At ~50psi minimum "per layer" is a LOT of pressure.
The OPs job has a lot of surface area, over 1,300 square inches, at 50psi you can do the math.
It really IS a job for epoxy should one want to laminate.

[mlydon]

You could also look up timber framers in your part of Georgia, call ‘em up and ask where they get their Timbers. Maybe they’ve got an extra lying around……

Matt

[Pauls]

Regards clamping and clamping pressure:
1. Clamps that will provide adequate pressure for 1 layer will provide the same pressure for any number of layers. The PSI is NOT reduced when more layers are added. They all see the same pressure because they're all being compressed together. The only limitation on gluing up a number of layers at the same time is the ability to spread on a lot of glue quickly. Use an adhesive spreader which is a straight edge with closely spaced notches. These give a very even distribution of glue and they do it quickly. Having a few helpers is a must on a job of this size.
2. You could use oak bars for all thread clamps, but lengths of steel rectangular tubing or pipe will be cheap and very stiff. As Bowdrie said, you want a decent size cross section for high rigidity. If you use pipe have a strip of wood under each pipe to prevent local crushing of the wood fibers.