Hardwood transom-oak dowels or galvanized pins?

[Landrith]

I have a one inch and three quarters thick air dried Black Walnut slab. Yes I know why not Walnut. It was free to me and I have a lot of unused West 105 Epoxy to soak it in. I want it to stay dark in the sun, so a pigment added to the epoxy, or a dark stain to the Walnut before the epoxy, then multiple coats of spar varnish is the plan.

The Black Walnut plank turned out to be slightly narrower than the 15 inch depth, 20 inch breadth hardwood transom I envisioned. So I am looking to join it with one horizontal joint after cutting it in two vertically. I will use epoxy or tight bond. I knew about oak dowels to strengthen and align the joint. Then I saw a Bristol Shipwrights Youtube on a skiff where they cut the heads off of hot dipped galvanized bolts and used them in a polyurethane adhesive out of a tube

The transom connects to an approximately 4 inch horn timber with a single knee (thus the thick transom). I would like to think this is a go anywhere boat. But it is being built in Kansas and likely will only see fresh water. The planking will be cedar strip edge nailed with galvanized and glued with _______

[wizbang 13]

eyeroll
WEST 105 duz not "soak in ". full stop
WEST 105 under varnish is a BAD idea.full stop
Adding pigment to 105 is daft ,putting 105 over stain is also daft. ...where you come up with this ?

You are going to build the transom of 3, 5 inch wide planks....I got that right?
Bonded drifts ARE a thing...but use the freakin epoxy ya got for that , NOT devil sperm (5200) or oak freakin dowels. That crap is for yer kitchen table in the house.
"Cedar strip edge nailed."...ya mean strip planked ...again, use the epoxy you have for this...sheesh.
fer god sake, just strip plank the wee transom same as the hull, even if coffin wood is your choice.(expect a BLACK and rotten transom in a decade).
I hunted 2 pages of your posts trying to find anything mention of what boat this might be ...or mention of any boat for that matter. ....zilch.
A lil background maybe ?
bruce

[Landrith]

eyeroll
WEST 105 duz not "soak in ". full stop
WEST 105 under varnish is a BAD idea.full stop
Adding pigment to 105 is daft ,putting 105 over stain is also daft. ...where you come up with this ?

You are going to build the transom of 3, 5 inch wide planks....I got that right?
Bonded drifts ARE a thing...but use the freakin epoxy ya got for that , NOT devil sperm (5200) or oak freakin dowels. That crap is for yer kitchen table in the house.
"Cedar strip edge nailed."...ya mean strip planked ...again, use the epoxy you have for this...sheesh.
fer god sake, just strip plank the wee transom same as the hull, even if coffin wood is your choice.(expect a BLACK and rotten transom in a decade).
I hunted 2 pages of your posts trying to find anything mention of what boat this might be ...or mention of any boat for that matter. ....zilch.
A lil background maybe ?
bruce

I am trying to do the transom in two planks. Hadn't thought stability would have been improved in 3 or 5.

I have a decade of excerpts from your experiences Wizbang, condemnations of non epoxy glues by Smalser, the heresy of PL Premium products as a glue for strip planking WRC espoused by Debenriver, and as bedding compound and bottom coating advocated on BoatDesignNet and here by sdowney717. Your DF strip planking with galvanized nails and no exterior glass seemed very attractive, along with references to the cedar strip planked no glue and galvanized nails of Jamie Hascall's 30' Wm. Garden sloop that has been mentioned in threads over the years.

Your discussions on fighting rust from galvanized are a basis for glass in epoxy sheeting as you have in the past suggested. I have someone else's Hartley TS 16 on the farm where the sheeting has delaminated from the plywood. I am not into plywood or composite monocoque boats. I have seen the discussions on silicon bronze nails vs galvanized and that neither are what they were. That is why on cost, I decided galvanized and cedar strip planking with no sheathing.

The knee will probably be Osage Orange, you have cursed your white oak. My local small mills are catering to the fru fru slab table market and had our attempted transactions been in person, I am sure it would have come to blows. I told them the oak I wanted wasn't for a wall hanging at New York's Museum of Modern Art. They took great offense. So for now I am just scavenging from the local cowboy fence post and firewood foresters..Our natural Black Locust is in shorter useable pieces than the European bug free plantation grown stuff marketed in specialty lumber dealers.

I am slowly building a keel sailboat, I have a mint Johnson 9.9 in the basement and my lakes are Lake Perry in KS, Lake of the Ozarks in MO, and Grand Lake, OK. But the exciting port of Kansas City, KS and the world beyond the Kaw beckons...

I am not working from someone else's plans. So I post questions in the the design section. If I get a little farther along, I will replace my profile pic's fiberglass windmill with the new boat.

[John Meachen]

A galvanised bolt with the head removed leaves bare steel exposed.Is that a good idea in a boat?Hardwood dowels seem like a better idea.

[wizbang 13]

Pretty much anything built of 2 planks will be more stable with 3 or 5, all the way down to a bunch o square planks.

[timo4352]

I vote for galvanized pins, 3/8" ...and epoxied in.

[wizbang 13]

^ dat look a tight fit, way de epoxy go ?

....is that ....? ugh ...oak?

[jpatrick]

The boards for the transom are only 20 inches long so it shouldn't be a problem to simply edge glue them without any internal pins, splines, bolts, nails, etc. Use a couple of exterior cauls to keep them aligned if you must. Titebond 3 will glue the hardwood perfectly in this application. It's water cleanup and non-toxic. I've glued many panels, much larger, in this manner and not one has ever failed.

Jeff

[Landrith]

The boards for the transom are only 20 inches long so it shouldn't be a problem to simply edge glue them without any internal pins, splines, bolts, nails, etc. Use a couple of exterior cauls to keep them aligned if you must. Titebond 3 will glue the hardwood perfectly in this application. It's water cleanup and non-toxic. I've glued many panels, much larger, in this manner and not one has ever failed.

Jeff

I had a titebond iii bottle I was going to try awhile back and it got hard. I would of course get a new one. I assume you plane the faying surfaces smooth and don't sand to get any kind of tooth? And have plenty of clamping pressure? I was wondering how epoxy with minimal clearance held up, that is why I was thinking the dowels or drifts like Timo shows.

[lupussonic]

Why not router square laps along their length, they will give you a larger glueing area negating the need for any metal in that join at all.

?

[debenriver]

I am trying to do the transom in two planks. Hadn't thought stability would have been improved in 3 or 5.

I have a decade of excerpts from your experiences Wizbang, condemnations of non epoxy glues by Smalser, the heresy of PL Premium products as a glue for strip planking WRC espoused by Debenriver, and as bedding compound and bottom coating advocated on BoatDesignNet and here by sdowney717. Your DF strip planking with galvanized nails and no exterior glass seemed very attractive, along with references to the cedar strip planked no glue and galvanized nails of Jamie Hascall's 30' Wm. Garden sloop that has been mentioned in threads over the years.

Not quite sure what i'm supposed to have espoused here?? Certainly not PL glues. WRC as the inner skin of a epoxy composite hull with two or more outer diagonal veneer layers, all epoxy bonded and coated is, and has been for some 50+ years, an accepted method of cold-moulding a boat hull. Boats we built in the late '70's and early '80's are testament to that.

But if you are not going to epoxy coat (OK - encapsulate) the hull structure, then you need to allow for some movement of the timber as it shrinks and swells. Personally. with a transom 1¾" thick I certainly wouldn't fuss with dowels or pins – and certainly not galvanized bolts with the heads cut off. Bronze pins if you must, would be much better. But at that thickness, just edge glue the two pieces – I would use epoxy as you don't need excessive clamping or a perfect edge finish. Rebating the join as suggested by lupussonic would also be a good system. It's not difficult to keep the two pieces aligned using strips of timber covered in parcel tape or similar (so they don't get bonded to the transom timber).

As Bruce suggests, varnish over epoxy coating is not that great in terms of protection against UV – and there seems little point in epoxy coating the transom anyway – just varnish it. Again, personally, I wouldn't stain the transom (either under epoxy of varnish) but I don't suppose it will do a lot of harm, though in later years scraping the varnish etc., may produce a patchy effect.

George

[Landrith]

No epoxy coating, just varnish sounds easier. I am big about being easy. So, a real marine varnish and not big box poly spar varnish will probably be worth buying. I don't know where I got the idea you were a pl premium strip plank advocate.

I will quote one of the notes I have:

Good God George! Quanon was right , they have already cloned and replaced you with an imposter:

"Yep, western red cedar for strip planking. It's available in long lengths and straight-grained with little runout. Just be careful when putting screws in the hood ends--the wood is somewhat brittle. But with proper clearance holes it'll be OK. You don't have to mess with epoxy for gluing. Titebond, Elmer's, or yellow carpenter's glue is a lot less trouble, and will do the job well with easier cleanup. Whatever glue you use, it's very difficult to achieve water-tightness in strip planking. That's why you cover it with glass. It resist abrasion better, too.

09-29-2002, 12:20 AM #5 Bayboat's Avatar Bayboat Bayboat is offline
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http://forum.woodenboat.com/showthre...strip-planking

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debenriver
Senior Member"

[wizbang 13]

^ hoo ever wrote that doan know how to use epoxy

[David Satter]

I've always put a plywood spline in a groove on transoms , works well and things line up nice. With epoxy. Bracket,Gaul 012.jpg 1/4 inch ply

[willin woodworks]

TBII is perfectly good stuff. Plane the surfaces glass smooth and clamp the ever loving bejeezus out them. You will not be disappointed.
You could always spline as suggested but that feels like a long run for a short slide.

[Landrith]

I've always put a plywood spline in a groove on transoms , works well and things line up nice. With epoxy. 1/4 inch ply

I used my stimulus money to buy used American made machines and tools. I look at the splines and agree that in some ways it is easier than dowels or drifts. To me it means pulling the Shop Smith Mk VII and attachments I buried under the motorcycle parts along the garage wall. The farm has a barn I want to build in at a different location, otherwise I might be converted.

Plywood of a different species set is probably more dimensionally stable that a simple cut spline or dowel of the same species. I guess you are getting strong joints on thin epoxy glue lines because epoxy penetrates a little deeper into the wood than other glues?

[Landrith]

TBII is perfectly good stuff. Plane the surfaces glass smooth and clamp the ever loving bejeezus out them. You will not be disappointed.
You could always spline as suggested but that feels like a long run for a short slide.

Minimal tools sounds goods but real clamps will be required. I do have 4 harbor freight pipe clamp sets and pipes. Also Whizbang got me serious about cutting my wood into at least 3 planks. So the real clamping will be needed.

[willin woodworks]

Plywood of a different species set is probably more dimensionally stable that a simple cut spline or dowel of the same species. I guess you are getting strong joints on thin epoxy glue lines because epoxy penetrates a little deeper into the wood than other glues?[/QUOTE]

Nope. Epoxy doesnt penetrate. Most glues dont. Epoxy forms a mechanical bond with the wood and does not react well to high clamping pressure. Epoxy benefits from poor joinery and rough bonding surfaces. It needs "X" amount of mass and some tooth to the gluing surfaces to create a strong glue joint.

PVA's and resorcinols do best when you can squeeze as much of the adhesive out of the joint as possible. The chemical bond is created best under high clamping pressure.

[David Satter]

Yup, I agree with Willin, you don't want a glue starved joint with epoxy.

[Mike Seibert]

FWIW - I did a number of laminated frames for my home built Lightning. My laminations were probably too thick because I had to use a good bit of clamping pressure to get them to take the shape. And I was concerned about having glue starved joints. The West tech guys recommended giving all glue surfaces a good coat of epoxy and letting it dry for awhile before doing the rest of the glue job. They said that would remove the danger of starved joints and I could then use as much clamping pressure as I needed.

I used hardwood dowels in my transom. They didn't make the joints any stronger but made the glue jobs a lot easier.

[jpatrick]

PVA glues do require a good clamp-up but I suspect this is more to bring the pieces into close proximity more than needing pressure for pressure's sake. One can do a good rubbed join on small pieces of wood that require no clamping whatsoever. And, I've edged banded miles of cabinet door and drawer edge trim by simply holding it on with masking tape. Close fit-up is more important than clamping pressure.

If one can't accomplish this, then epoxy is the only real alternative. But, the glue seam will likely become obvious.

Jeff

[willin woodworks]

The thicker the glue line with PVA's like TBIII the weaker the joint. Edge banding cabinet doors requires nothing more than adhesion. Gluing up a transom or frames requires strength and that is done with clamping pressure.

[P.I. Stazzer-Newt]

T&G the boards.... - whatever gle you fancy - make certain that the boards are dry to eqilibrium - or splits will happen.

[timo4352]

I don't trust an outboard hanging on a glued joint....