Putting a mast in a Whitehall - thoughts?

[cmcgovern]

Hello folks, I've been lurking for a while. I am making my first boat, a Glen-l whitehall, and plan to do a sail rig. Glen-l is sparse with details and suggestions for how. (Their official plans do not include a sail rig).

They offer this:
http://www.glen-l.com/designs/canu-row/whitehall-notes.html

I know I will cut a hole in a thwart. But I want to know, what is the arrangement down at the base of the mast (at the floor) for securing it? I want it to be an unstayed mast (no lines from the top).

So anyone with pictures or diagrams on similar boats, please help me out!

here's a diagram of the boat. I am doing it as glued and encapsulated cedar strips. And I will post more pictures when I have something to show!http://www.glen-l.com/designs/canu-row/canoe-row-images/dsn-whll.jpg

[Bob Smalser]

Not planning on a centerboard to go with it?

John Gardner's Volume I has a detailed plan for a 14' Whitehall with CB and mast step that should serve your needs. You can use either solid and drifted or ply and glued to match your construction.

An effective design is a mast step open at the bottom for drainage...

http://pic20.picturetrail.com/VOL12/1104763/7099973/266881623.jpg

...with oak reinforcement for the thwart hole that laterally supports the mast, this one mortised to fit the CB trunk:

http://pic20.picturetrail.com/VOL12/1104763/7099973/103642436.jpg

http://pic20.picturetrail.com/VOL12/1104763/7099973/292499981.jpg

[Jim Ledger]

:eek::eek::eek:

B-C ext. fir ply for the mast step?!!!

Not worried about sapwood in the plies?

[Bob Smalser]

...fir ply for the mast step?


An excellent application for thick marine ply. No danger of splitting. Laminate pieces to the thickness desired and finish with CPES followed by red lead primer and enamel, and it'll last a long time and be easy to replace when the time comes.

Repairability of CB trunks and mast steps is important, as these highly-stressed areas are often the first parts to cause problems as the boat ages. Even in a glued-lap plywood boat, I'd use solid trunk logs and mount these parts using traditional bedding compound and screws rather than glue, so it can one day be dismantled with a brace and screwdriver bit instead of a Sawzall.

[cmcgovern]

Oh- duh - forgot to say, yes, I am planning a daggerboard actually. but again I don't have specifics yet.

Thanks for the pics! Anyone else have something to add?

[Yeadon]

Take an afternoon and run up to CWB (http://www.cwb.org) in Seattle. It's a great place for this type of research. Crawl around the inside of their little boats, and you'll see a couple different type of mast steps. They do have a Whitehall "Jenny" with a sail rig up in storage, but you'll see everything you need down on the docks, too.

[Bob Cleek]

Generally not a good idea because a "whitehall" wasn't designed to sail. The trade off between good pulling boats and good sailing boats is beam. Narrow beam is what you want for a pulling boat. Wide beam for a shallow sailing boat. Always, it's a compromise.

I would NOT suggest that anyone other than a very experienced designer waste their time trying to convert plans drawn by a competent marine architect. If a boat was meant to sail, it will have a sail plan with the architect's drawings.

If you want a "whitehall" looking boat that both rows well and sails adequately, you should examine the Herreshoff 12 1/2' Columbia "lifeboat" design. WB Store sells a small book that tells you how to build it, with or without a centerboard and mast. It is pretty much what you are looking for if a "sailing whitehall" is what you want.

http://home.att.net/~w.landahl/HerreshoffDinghy.jpg

http://northbayboatworks.com/BoatsBuilding/Herreshoff/Herreshoff1.jpg

http://ecx.images-amazon.com/images/I/51CSBT3SD8L._SS500_.jpg

The Columbia dinghy knock-off "Catspaw" dinghy is quite similar and you may find it an easier boat to build, although lacking in the true character of the original.

http://www.woodenboatfactory.org/Current%20projects/images/cat.jpg

[cmcgovern]

Well, gosh, I understood it was a compromise - I knew it would never be a performance sailer - but I thought it would at least be doable. This is frustrating to hear, because Glen-l's site makes it seem a simple matter. Is it an issue of the boat tipping over? would a weighted daggerboard help? I know it won't tack across the wind, that doesn't bother me, I just wanted some help going straight...

I already have forms set up, I don't want to change the boat now... :(

[Canoeyawl]

One of the problems will be the lack of rocker. It will be difficult to tack.
Sailing whitehalls have rocker and an increase in beam.
See Chapelles book for details, he shows both types.

[Yeadon]

The Glen-L site you offered mentions that it's fine to shorten up the 16'11" LOA about 10 percent. I'd think that a 15' foot LOA craft along with a 4'6" beam, with a dagger board, and sprit rig -- well, that sounds like a good little row/sail boat to me.

I'd consider finding sail/rig plans for a similar sized boat and transferring the dimensions to yours, and making sure that you don't change the relationship between the mast step, the sail's Center of Effort, and the dagger board.

For instance, I took the Catspaw sail rig design by Joel White and implemented it into my 15 foot peapod. Works fine, I can even get a bit of windward performance by messing with sail trim and human ballast. I still have a bit of tweaking to do with the rudder, but that's the fun of it all.

I believe that if you do your research, it is fine to tweak the design of a small wooden craft. After all, it's just a little boat. Build it. Use it. Report your findings back to the forum. (And remember to use some common sense while you're out on the water, and you'll be fine.)

[cmcgovern]

Thanks, Yeadon, for suggesting it could work... I have to ask, why is it important to shorten the length? Better turning ability?
Edit: Oh, wait, i think I get it... better beam : length ratio. right?

[Thorne]

You certainly can rig a Whitehall for sail, it is done all the time. They tend to be difficult to tack, as the hull design that makes them track well under oar also makes them track a little too well under sail...

;0 )

http://www.whitehallrow.com/boats_img/tyee_14_sail_med.jpg

As Yeadon suggests, check out (photograph and measure) all the Whitehalls you can, as that will answer a lot of questions and possibly save you a lot of effort and $$.

Bob Smalser knows his stuff, and his advice and web 'articles' were a great help to me when I rigged my pulling boat (a Chamberlain dory skiff) for sail.

I used two 1" thick by 5" square pieces of white oak left over from my rudder to make my mast step -- but drainage isn't as good as the example Bob shows -- and good drainage is critical in small open boats!

I used a hole-saw to cut through both pieces of oak, drilling a horizontal drain hole in the bottom piece. I screwed and epoxied the bottom piece to the floorboards, then screwed and glued the top piece on, offsetting the screwholes, of course.

http://www.luckhardt.com/dory1.html

If you are going to use a spritsail, the mast must rotate in the mast step and partners, so plan on leather-lining the partner hole, and leaving enough room for the wood to swell slightly without locking the mast into place.

Here's a whitehall set up for sail on SF Craigslist -
http://sfbay.craigslist.org/nby/boa/503126533.html
http://images.craigslist.org/01010901020101030820071208f40e8e0f151989146f0009ef .jpg

The mast looks a bit far aft to me, but that all depends on where the centerboard is located.

My suggestion is to get the best measurements and advice you can, then build the centerboard or daggerboard first. Once that is completed, you can then tweak the position of the mast to get a good balance between CE (center of effort for the sail) and CLR (center of lateral resistance). <--vastly simplified of course

Given a fixed CLR (center/daggerboard and rudder), having the CE too far forward results in lee helm, and having the CE too far aft results in weather helm == neither of which you want to experience in the extreme.

You may want to rake the mast forward (can be risky to rake it back very much) to offset any balance issues, or even put in a separate mast partner if the thwart isn't in the right place (or you want to 'save' the thwart for sitting under sail).

http://www.whitehallrow.com/articles/sailing.php

[Yeadon]

Edit: Oh, wait, i think I get it... better beam : length ratio. right?

That was my thought ... that the new ratio would give you a bit more stability through the bilge while you were out sailing. (Also, in Washington State, you have to register and get tabs for any boat over 16 feet. So, it pays to shorten her up a bit.)

The boat's lack of rocker is a fair thing to question, I think, but not a deal breaker. I wish my peapod had a lick of rocker, but I'm not exactly a performance-minded sailor.

I'd love to hear what an actual designer thinks about all this, of course.

[dmg]

Try Great Lakes Wooden Boats- Michael Kiefer, and Gull Lake Wooden Boats- Bruce Hutchinson. Both have built sailing Whitehalls.

I built the Glen-L 17' Whitehall as it was drawn. Sailing version was for future model. You need a wider keel for sure for the dagger board box. The rest is added inside the hull after you flip it over.

Dave

[adampet]

You may want to consider a whitehall as a down wind sailor. Local Photographer Barry Donahue has a Washington County Tech School whitehall with a sailing rig. It's traditionally built, cedar on oak. It has no center or daggerboard and will sail only about a close reach. Anything closer to the wind he rows. He does tack it by pulling on one oar until it comes through the wind. His boat does have a fairly deep keel. I don't know what the Glen-L has for depth below the waterline, but it does show that whitehall long keel.

So go ahead and put a sail in it. Bob's advice of mast step and thwart reinforcement are right on the mark. But understand that it's not designed to be a sailboat, and adding a hole in the bottom will affect the rowing characteristics.

And we all are picturehounds, so when you have some to show, post them.

And welcome!

Adam

[KMacDonald]

You may want to take a look at this sailing whitehall:

http://www.dhkurylko-yachtdesign.com/designs.htm

[Eric Hvalsoe]

Historically Whitehalls sometimes used sail downwind, no board. Might even be enough lateral plane in this boat for a good reach, close to broad without a center or daggarboard. It is also true that many 'Whitehall' types have been set up with the full meal deal. I would not exactly say that shrinking the boat (length) makes it more stable - in large part stability is determined by beam, but also by how hard or soft a bilge, and flair above the water line. Shrinking the lengh might make the hull proportionally fuller in the ends and so possibly less tender in terms of fore and aft trim. I'd want to see a midsection to offer any opinion on how the design would stand up to sail. Someone pointed out that a case in this whitehall might have to be off center, with the board piercing the plank. The mast of a sprit rig does not have to rotate. I happen to use a square tenon in my 13 and 16. Certainly important that the mast step drains, I have laminated mast steps with oak or apitong and bolted (not glued) through the keel, mortises are about 1". Of course quality plywood would do as well. The mast thwart on the Hvalsoe 16 is forward of the trunk, it is doubled with marine plywood, and the plywood is mortised into the seat riser. The seat riser itself is doubled up in this area. One set of knees for the mast thwart. I keep the seat riser relatively high and parallel to the sheer, Holds up 85 sq ft of sprit. This is in reference to traditional lapstrake hull, largely applicable to a stripper. Yeadon did well dropping a catspaw rig into his peapod. My 16 and 13 were designed from the get go with rowing, trunk, and sail positions balanced. Recommend tying a trunk to a thwart - also vote for bedding and fastening rather than gluing the trunk in place. The behavior or feel of the helm is the result of the position of the rig relative to the underwater portion or profile of the hull, including the board if you've got one, and rudder. One of the fun things about these small boat is that thier balance is greatly affected by live balast - that's us. Indeed the long straight keel of a whitehall type makes them slow to tack. Look at a number of boats and designs with rigs, right up live like at the Center For Wooden Boats, there are things out there to read about design and balance. Or have a one on one conversation with a good boatwright and/or designer. I think you can get a pretty good idea by looking around.
Eric Hvalsoe

[Woxbox]

Common folks. Of course you can sail a Whitehall. How is it we get people in this forum drooling over sailing canoes, which are very skinny and have no rocker to speak of, and yet they're fast and tack and go to windward, and then we turn around and claim you can't make a Whitehall sail?

The Whitehall is narrow, but that means it's more easily driven, so you use a smaller sail, and go with a sail that carries a low center of effort. My Whisp up there on the left weighs about 80 pounds, is about 4 feet wide if that, and carries 73 square feet of sail. And with her leeboard, there's no hole in the hull to affect rowing performance. It works. End of story.

BTW -- as an experiment I made the mast step out of a chunk of oak and 5200'd it to the sole. Hasn't budged.

[katiedobe]

Right on Woxbox!
But I would still build my mast step and partner as Bob shows. I hate to deal with 5200 and wood in the future.

[Anthony Zucker]

Wouldnt leeboard(s) be a good approach? They can be moved fore and aft to find the right location and dont require the trunk. I'm looking at the CLC Chester Yawl which looks like a whitehall and think that leeboards might be the easiest way to rig it for sail

[cmcgovern]

The Kurylko boat makes me drool, the Hvalsoe boats make me drool. Wish I wasn't already in the middle of this one. Thank you, everyone for your input... Thanks Mr. Hvalsoe, great stuff there. I will do as you say and look at several similar boats for inspiration. to be continued...
oh, by the way, if people want to see more pics of this boat, go here
http://www.glen-l.com/designs/canu-row/whitehall.html
and scroll down to 'photographs'.

unfortunately, Mr. Zucker, I loathe the very thought of leeboards and won't be caught dead with them.

[Bob Smalser]

The problem with tinkering around with a design is fixing what doesn't work well after you're done.

Gardner has a minutely-detailed and proven plan for a 14' sailing Whitehall with a 4' 2" beam and low sprit rig with jib that could easily be scaled to the dimensions of the Glen-L boat. The boat uses a deepwater keel and off-center board.

In lesser detail he also shows a sprit rig design sans jib for a 17' Whitehall with a 4' 4" beam and a CB mounted in a plank keel, but a little work with proportional dividers could also scale that design to your boat.

A dagger board takes up less space but in a boat of any size is real hard on the trunk and keel when it hits something.

[Andrew Craig-Bennett]

What Bob says.

[Ian McColgin]

I respectfully disagree with Bob as a downwind sail is dirt simple and gives you a nice rest. Nothing makes this design a good sailer - no bearings aft.

The hull is resistant to leeway given it's long keel so she'll tight reach easily if you get your weight and sail trim right.

Sail her like a St Lawrence, moving forward and trimming the sail to bear up, aft and easing to bear off.

Sail design is practical. The largest will have a sprit about as long as your outboard most duckboard as that's the longest that can be laid along the thwarts off-center letting you row with the rig struck. Better would be to have a shorter sprit that will slide under the aft most thwart and then lay off-center. The bird's eye mast will be a tad shorter.

I'd put the partner reinforcement of the thwart and the step below it right up in the bow through the foremost thwart. She'll get to a tight reach even with the sail way up there as you can move crew weight aft. It'll be especially for "ash-motorsailing" down wind or reaching in really light air.

I know this works as I made such a rig for a Whitehall in Boston. Made a nice way for a woman and her small kids to fool around all over from Chelsea down to The Graves and back.

Just keep in mind that the Whitehall is an excellent pulling boat, not really a sail boat. Don't expect her to work to weather with a Swampscot dory or anything.

G'luck

[Eric Hvalsoe]

I like Ian's comments about a downwind rig. I'm not sure I would put the rig that far forward, I would look at the CE and CLP - then again, he has set up this particular deal. Approach shrinking and expanding designs with caution and a good eye.
Eric Hvalsoe

[cmcgovern]

Mr. McColgin: I am not too familiar with the st. Lawrence skiff, but are you saying, no daggerboard, no rudder, just sail by shifting weight?

[Ian McColgin]

They are really cool - very long and narrow for easy rowing. THe guides would take their "sports" fishing along the myriad islands and passages and, among themselves, developed a unique sailing technique. Some St Lawrence River skiffs had centerboards as the rigs got bigger and beating to weather became a goal. But never rudders. Depending on the sailor's weight, tacking might mean going up to the mast or even around it. Trimming and racing foreward began the turn and the idea was to keep the boat turning through the eye of the wind on momentum and then veering off by easing the sail and racing back astern. I don't know if this became normal practice but during my own all too limited experience with the type, I found that it helped to essentially roll tack from the bow to fool the sail and boat into thinking it had to go further up wind, driving past wind dead ahead with the sail still full. I got the idea from pictures I'd seen.

I'll be there's someone on this forum who has lots of St Lawrence River skiff experience who can explain more fully than my limited and untutored experience.

[Bob Cleek]

Yes, you can hang a bedsheet on a couple of crossed broomsticks and it will take you downwind in a rowboat just fine. As Smalser says, though, fixing what don't work is the worst of it. I'd add that the smaller the boat, the less forgiving it will be of errors resulting from design changes.

I now realize the original poster is already committed to the Glen-L design. Yes, Glen-L makes it seem easy: "Build your dream boat and save!" they tell you. Well, that's not false advertising. There have probably been more Glen-L boats built "in your dreams" than any other outfit's.

When it comes time to build your next boat, do a little research and you will almost certainly find 1) exactly the boat you are looking for (assuming you don't change your mind and want a sail boat after you've framed a rowboat...) 2) that has evolved through many years of trial and error to do exactly what you need it to do and 3) which is a proven design that can be depended upon to perform well. Given what is available in the public domain, I never cease to marvel at those who actually spend money for small boat plans and kits and then want to monkey around redesigning them to be something they aren't. Each to his own, I guess.

[Thorne]

I think you've got it all wrong, Bob.

The Glen-L site clearly shows a sailing rig for the boat, and indicates the plan can be used for building the boat to sail.

This is NOT the usual "project creep" that I've made fun of in the past, where the builders wants a boat that can be rowed easily, sleep 10, cruise the ocean, be cartopped, and costs under $200...

;0 )

This guy looked at the Glen-L plans and picked a boat shown with both rowing and sailing options. He's now politely asked us about the sailing conversion, as it turns out the Glen-L plans don't give him much information.

I did the same thing -- converting a pulling boat for sail. I worried that it would be horribly tender, ruin the boat for rowing, and waste my money and time.

The result so far has been wonderful far beyond my wildest dreams. The boat sails nicely, still rows well, and gets hauled all over the northern part of the state to various events.

So, other than going with Glen-L rather than another more modern and popular designer like Arch Davis, John Welsford or Ian Oughtred, I really don't think he's done anything wrong. And he's certainly come to the right place for advice...

[cmcgovern]

Appreciate the support, Thorne! You have it right. I know there are different camps in the wooden boat community but we all share the same love. Me, I figured this project as a relatively painless way to get into boatbuilding. On my NEXT boat(s) I will try for better precision.

For now, I am seeing a lot of net photos showing similar boats with a board dead in the middle of the lwl and a sprit rigged mast way up front. I understand the risks of modification. I will not be super-mathematical about it but, as suggested, make some careful visual comparisons and proceed with caution. Maybe I'll make mistakes and learn from them. It is likely to perform well as a rower even with these changes and even if sailing fails. With luck I'll have a good experience like those here mentioned.:)

It certainly won't be the worst thing anyone's ever done in boatbuilding. (see here: http://en.wikipedia.org/wiki/Vasa_%28ship%29 )

[Yeadon]

Just curious, how wide is your keel/keelson assembly? Will you have enough width for a daggerboard trunk?

[Thorne]

I was looking through my collection of boatbuilding books last night, and remembered "Building Catherine" by Richard Kolin.

Might be worth buying a copy from our kind hosts, as the design is a modidifed Whitehall with no rocker and rigged for sail. The specifics for the 14' x 4' hull would be different, but many of the book's instructions and dimensions for the sail, spars and daggerboard should be spot on for your build.

http://www.woodenboatstore.com/images/325118.JPG

[Bob Cleek]

Well, hell, if the designer shows it with a sail plan, then call them up and demand they send you some decent plans!

[Ron Paro]

Mine is not a Whitehall, but here are some more pictorial examples of a mast step and dagger trunk. The mast step is 2 pieces of 9mm okoume ply laminated together, and then attatched with bronze screws to the oak risers for drainage. Four bronze screws are driven through the bottom of the hull into the risers, which were bedded in thickened epoxy. The mast partner is a 9mm reinforcement block epoxied to the bottom of the 9mm deck and the Douglas Fir deck beam / splash rail. The dagger trunk is attached to the center thwart.

http://bp1.blogger.com/_XuaT2XHyCMw/RfS44ztIrxI/AAAAAAAAAMk/Teq098joNEM/s200/IMG_2996.JPG http://bp2.blogger.com/_XuaT2XHyCMw/RoLSPye7AbI/AAAAAAAAAWc/UK_aqe0jUdA/s200/IMG_3466.JPG http://bp0.blogger.com/_XuaT2XHyCMw/RoLJzSe7AJI/AAAAAAAAAUM/D2LuOlKolww/s200/IMG_3437.JPG http://bp2.blogger.com/_XuaT2XHyCMw/RoLLiye7ALI/AAAAAAAAAUc/ykjiSAc0d9Y/s200/IMG_3439.JPG

This is a 13' 2" Jimmy Skiff, and the beam is 50". I have since re-run the halyard and snotter lines through fairleads down either gunwale, with clam cleats to hold the lines near the center thwart. This way, I can easily make adjustments while I sail single-handed. This is a very lively little boat with good sailing and rowing characteristics.

Ron - http://jimmyskiff.blogspot.com

[Doug Hamilton]

Here is a graph that pertains to scaling an old hull in order to loft a new one that is "suitably" proportional..By using the new length over all (LOA) to determine its proportion of the old LOA a corresponding proportion of the old half-breadths can be found for the new half-breadths..Where the new LOA is within 15% of the old LOA it appears not to make much difference whether you apply to the half-breadths that same proportion of the new to the old LOA or use the chart and find a corresponding proportion that is within about 10% and apply that to the half-breaths.

The proportions of both the LOA and the half-breadths of the three boats cited in this thread relative to the same dimensions of the Glen-L boat are plotted to afford a comparison of one to another.. For instance, if the Glen-L proportions represent the ideal, Gardner's boat that is 0.823 times as long should have half-breadths, according to the graph, that are 0.86 times as wide as those of the Glen-L boat, not 0.936 times as wide.

There are other lines (curves) that can be plotted on the grid of this graph.. They yield factors that can be similarly applied to the height of the mast, to the weight of the canvas, to the areas of the sails and to the displacement, the weight of ballast and the power of an auxiliary engine.. The factors derived for these other components of the boat are more at variance with the ratio of new to old lengths than the factor for the half-breadths shown on this graph.



http://i73.photobucket.com/albums/i207/Dougha/s3.gif

[Classic Boatworks - Maine]

[QUOTE=Bob Smalser;1711257]An excellent application for thick marine ply. No danger of splitting. Laminate pieces to the thickness desired and finish with CPES followed by red lead primer and enamel, and it'll last a long time and be easy to replace when the time comes.


If we might interject, use either red lead or CPES. The CPES really doesn't soak in far enough, so we would really go with the red lead, but not both.
Marshall

[Eric Hvalsoe]

Good point using CPES or red lead, you feel that red lead actually penetrates more than the epoxy?

[Ian McColgin]

Why put red lead over CPES, a perfectly good sealer, primer and preservative by itself?

CPES really penetrates quite deeply and many of its solvents penetrate more deeply. My friend with the much redone Wianno had occasion to drill new keel bolt holes through the wood keelson that had been CPES'd about 5 years or so earlier. One could still smell the CPES odor in the drill shavings coming up and they were a couple inches in from the edge of the keel, to that's penetration through side grain. Penetration through rotary cut will get through the first ply and up to the glue line while penetration from end grain will travel and travel and travel. On 3 ply 1/4" plywood planks about 4" wide I've had CPES get from one side to the other through that center ply.

Red lead, on the other hand, just lays on top. Red lead (or white) is quite nice in a traditional bilge for it's mild and utterly non-volitile toxicity. It's also nice as a primer before putting copper based bottome paint on an iron fastened boat.

[Bob Smalser]

Good point using CPES or red lead, you feel that red lead actually penetrates more than the epoxy?

Both on plywood, which needs all the help it can get. The CPES inhibits the water intrusion responsible for delamming and the red lead inhibits mold in all those cheap sapwood lams hidden below the surface.

Natural wood just gets red lead.

[cmcgovern]

Am I right in thinking there is no occasion to use red lead on a fully epoxy-encapsulated cedar strip boat? i.e. not on the strip planking or keel?

[Thorne]

Well, we still don't know the materials you used in your boat, but I'll assume it was marine plywood.

I'd still used CPES and red lead on faying surfaces within the hull and on the boat in general, excepting the strips in the hull. As Bob says above, ply needs all the help it can get, and CPES will penetrate further into the edges of the ply than epoxy.

Unless you are coating all parts with epoxy before assembly, you will have wood touching wood -- thats a 'faying surface'. Coat these with red lead for the best protection against rot, even over CPES.

In my limited experience, rot in ply really shoots along the plies, and entire sections can seem to rot at once. Years ago I bought an old Glen-L sailboat in poor shape, and somewhere my wife has a photo of me coming through the hull with a crowbar -- it was completely rotted, probably built with non-marine ply in the 70's.

Solid wood seems to rot much slower, along the grain but unevenly. Either material should have the maximum protection against rot and water intrusion if you want it to last.

[Bob Smalser]

Am I right in thinking there is no occasion to use red lead on a fully epoxy-encapsulated cedar strip boat? i.e. not on the strip planking or keel?

I think so.

The issue with combining CPES or epoxy and red lead is whether the epoxy alone will prevent the wood from reaching the 20% MC threshold for rot. If it will, then the red lead is only really useful as a primer for paint (which is a stand-alone reason for using it BTW, as it's one of the best).

Cedar heartwood is one of the best woods for resisting mold and rot, and as a low-density wood remains relatively dry beneath a proper finish whether varnish or paint. The denser woods like oak remain wetter in service, and would be better candidates for using both. Plywood has longevity problems compared to solid wood caused by the combination of crossgrain glue joints and hidden voids and sapwood, and also benefits from both. But in a trailer boat that lives most of its life dry and under cover, these factors are minor and only come into play later in the boat's life when it's left out to deteriorate in the weather.