Gunnels

[Guest]

On the other thread you mentioned

I was also wondering if it possible to pull the hull in a bit...an inch? Two? This canoe will be paddled mainly solo now. I am thinking the more I pull in (if at all), the less stable it will become.

I have drawn in several canoes and inch or two. Both RX and composite hulls. The occasional wisdom is that you will hog the canoe or perceptibly alter the rocker.

I am calling nonsense on that. Reducing the sheerline an inch or two isn’t going to do bupkiss to the bottom shape or the rocker, especially on a firmed-up, foam core set in its ways RX hull. A 2 inch sheerline reduction over a 16 foot canoe is (where’s my calculator?) a 1/96[SUP]th[/SUP] change. If the hull has any arch or vee in the bottom shape that will be unnoticeable.

All you will do is add some tumblehome and make the chines sharper; I have yet to see the bottom hog or any appreciable change in rocker with an inch or two reduction in gunwale width.

The sharper chines will make the hull a little more catchy on eddy lines, but again 1/96[SUP]th[/SUP] isn’t much.

I drew in an older flared kevlar composite canoe by 4 inches total, two on each side. That had zero measured impact on the rocker or bottom shape. It did put so much stress on the now very sharp edges that the stretched gel coat on the chines spider cracked in moderately abusive use

On an old, set in its ways Royalex hull I don’t believe you will see anything except a narrower gunwale line and slightly sharper chines, and most of that newly induced tumblehome tuck-in takes place well above the waterline.

For a mostly solo paddled canoe, go for it.

 

[TheIndian]

Oh, I'm excited now LOL. Won't get greedy, maybe an inch.
Thx Mike!

 

[yellowcanoe]

I'm not calling the effect of drawing in the gunwales nonsense nor spreading them out
All is in context and not so simple

Done severely enough in a short daintily floored boat you will have hogging or increased rocker
But most hulls are robust down there. There is more fabric or Royalex is thicker in the bottomed football and the sides thinner walled

The envelope is often called on as an example but an envelope is all one thickness and a different shape

Custom builders often spread gunwales out or in an inch or two
I just saw a Colden Starfire that was altered to allow for more efficient solo paddling
This was done right after the canoe came out of the mold
Colden canoes are quite stiff and tolerate this well the gunwales were pulled in two inches
Some RX lite boats would change bottom shape

 

[pblanc]

I have pulled in the gunwales by a couple of inches on 2 Royalex solo whitewater canoes to facilitate cross-strokes. I could not detect any visible or measurable change in rocker.

I think the cross section of the hull bottom can be significantly altered, however. Consider as an example the Dagger Ocoee whitewater solo canoe. This canoe was later molded in Royalex by Bell, and finally by Nova Craft. I have a couple of friends who bought the Nova Craft version. When these boats started to appear, owners who had been familiar with the Dagger version noted that the hull was significantly narrower at the gunwales. The buzz is that Nova splashed a mold off of a Dagger or Bell Ocoee that had been pulled in by 2 inches or more for slalom racing.

The owners of the Nova Craft Ocoees found that although their boats were faster than the other versions, they were significantly less stable. I know of several folks who have spaced out their Nova Craft Ocoees by installing longer thwarts to match the original Dagger specs and the stability was markedly improved.

I doubt that an inch change would have any appreciable effect on hull cross sectional contour.

 

[Guest]

I have drawn in several canoes and inch or two.

I drew in an older flared kevlar composite canoe by 4 inches total, two on each side.

To be clear, when I say drawing in by an inch or two I mean reducing the overall gunwale width by an inch or two, ie moving the gunwales in ½ inch on each side equals a 1 inch reduction in width, etc.

I will stand by that reduction producing a bit more tumble home and slightly sharper chines while having zero appreciable effect on the rocker or bottom shape.

 

[latremorej]

I own a Bell Northwind in RX and I pulled the gunnels in 2 inches by taking an inch off both sides of the 2 thwarts and yoke. It made it easier to solo but I couldn't notice any change in paddling or fishing from it. I did notice however that my large beer cooler wouldn't fit anymore. After a few years the vinyl gunnels actually bent at the bolts, presumably from the preasure of the RX trying to get back to its original shape. This spring I carved new thwarts from a board of cherry matching the original width. I have yet to pull it out from the deck since my spring trip to see if the gunnels "fixed themselves" yet. I changed back to the original width for better volume on the family trip.

Jason

ETA:
When I say the gunnels bent at the bolts, think of tying up an old sleeping bag. Where the bolt was holding the thwarts in place on the gunnel looked like the string holding the bag from expanding... Make sense? Sorry but I don't think I have a pic

 

[TheIndian]

Great observation latremorej...I don't see the point of a canoe anyway if you can't get beer in it. Haha.
Just kidding.

I didn't get greedy...took it in 3/4in on each side.

At this point my gunnels are just about ready for installation. I am going to rely solely on Watco Teak for preserving the ash at this point. Last night I spent a few hours applying two or three coats of the stuff. Was wondering if that enough. Since it been 12 hours now since my last coat, was wondering if it not too late to continue to apply more coats. Would like to get as much oil in there as possible.

Your thoughts appreciated.

 

[pblanc]

I have a lot of experience with Watco oils, including their Teak oil. My experience is that with Watco oils, if you try to apply to many coats too quickly you risk winding up with a gummy mess. It is never "too late" to apply more coats.

A penetrating oil product that did allow you to apply many coats over a relatively short period of time is Deks Olje, which is unfortunately not generally available in the US anymore except on-line. I have found that my results with Watco are generally better if I apply two to three coats then wait a few days before applying more.

 

[TheIndian]

Great. From what I see so far it looks like the new ash has absorbed the oil well. Plenty of chores to do around here in the meantime so maybe I'll wait a little and apply additional coats tomorrow or the next day. Sure am anxious to get the gunnels installed but I know it worth the wait. Thx pblanc.

 

[Guest]

I own a Bell Northwind in RX and I pulled the gunnels in 2 inches by taking an inch off both sides of the 2 thwarts and yoke.
After a few years the vinyl gunnels actually bent at the bolts, presumably from the preasure of the RX trying to get back to its original shape.
When I say the gunnels bent at the bolts, think of tying up an old sleeping bag. Where the bolt was holding the thwarts in place on the gunnel looked like the string holding the bag from expanding.

With the gunwales removed there doesn’t seem to be a lot of resistance along the sheerline when pulling the hull in or pushing out an inch or two. The pressure or memory from the RX hull seems unlikely to bend the machine screws.

My experience may differ; I am usually soloizing a tandem when drawing the hull in, and typically install a truss hung seat and usually an extra thwart, sometimes two. Between the truss hung seat (where I prefer ¼ machine screws) and additional thwarts those canoes are uber stiff along the sheerline.

What can be a problem, and perhaps why your gunwales defomed at the bolts, is that the yoke and thwarts may no longer set level along the underside of the inwale when the hull is drawn in.

From the factory the thwart/yoke ends usually seat more or less flat against the underside of the inwale. __----.

When the hull is pulled in the gunwales tend to angle, canted inwards, ___/ (very out of scale, but you get the idea). A machine screw seated through the canted connection is under a lot of stress, as is the screw head and flange washer atop the gunwale.

Even with the factory thwarts and yoke flat fit a lot of the machine screws I have removed from old canoes were slightly bent. If they are wanked enough they can be a wobblewobble PITA to remove. Not a bad reason to double hang yoke ends using two machine screws on each end.

This not-flush-fit is worse with vinyl gunwales, especially those with a wide box inwale and a flat underside.

On the flared kevlar hull I drew in 4 inches the thwart to inwale fit was so far off that I made custom thwarts, shaping the under-inwale butt ends so that they fit more flush.

I’ll be curious whether the gunwales look any different. I expect there is an aluminum channel inside the vinyl inwale, and aluminum doesn’t have a much bounce back memory.

 

[TheIndian]

I have found that my results with Watco are generally better if I apply two to three coats then wait a few days before applying more.

Hey pblanc...after you've waited a few days, do you give the gunnels a light sanding before applying more Watco Teak?

 

[yellowcanoe]

Watco teak oil is not pure oil. Its a mix of varnish and oil.. It does not soak that far into the wood. Here are some hints for applying and sanding.
http://www.wwch.org/Technique/Finishes/OilFin.htm

 

[pblanc]

Hey pblanc...after you've waited a few days, do you give the gunnels a light sanding before applying more Watco Teak?

Yes, I will often sand with fine, wet or dry paper between coats. I usually use 1500 grit but you could use something a bit coarser, say 600-800 grit. You can also apply a thin coat of oil and wet sand.

I have found that no "penetrating" oil penetrates very far into wood, whether it has varnish in it or not, and I have tried quite a few different types.

 

[Jim Dodd]

I have found that no "penetrating" oil penetrates very far into wood.

True !
All I've ever used has been Watco, so I have nothing to compare it to. It beat polyurethane, in that when scratched, it doesn't leave a white mark like polyurethane does.

​ My method is different, I apply a liberal coat, wait a half hour, rub off excess. Apply two more liberal coats a day apart, and wait a month to dry.
I said it was different ! It is more like varnish, than a rubbed oil finish.

I'm always looking for a better easier coating.

Jim

 

[TheIndian]

No Title

Gunnels have been mounted to canoe hull. Now to install seat, portage yoke and kneeling thwart. Thanks for all your advice and help. I learned a lot.
In the meantime, I conducted a little experiment about the "penetrating" oils. I'll try to post pics but don't have a lot of luck with that.
Anyway, what I did was I took two short pieces of the gunnels that I made...about a 3 inches each. One I left alone, the other I submerged in Watco Teak Oil for 6 days. I then cut and exposed the interior of the piece that was submerged. The piece submerged was much darker in color through and through and also weighed considerably more (didn't actually weigh). I'm guessing you guys probably conducted an experiment like this already but the results were great. By the looks of the submerged sample, I think the oil completely penetrated every pore space in the ash. The next time I make gunnels, I will definitely try to submerge for several days. I had recently threw out an old section of gutter that may have been useful...next time.

 

[Jim Dodd]

After staining, I am considering the Watco Teak oil as well. However I read that it hardens when dry. Will the hardened Teak oil then prevent the wood from absorbing future applications of Teak?

Watco Teak hardens in and on the wood. A light sanding, and you can easily apply another coat of Watco, years later, if you desire.

 

[Mihun09]

The next time I make gunnels, I will definitely try to submerge for several days. I had recently threw out an old section of gutter that may have been useful...next time.

Mounted on a wall in my shop is two sections of 4" eavestrough that is sealed so I can soak rails or whatever I need either before steaming or just for a good soak. I mounted L brackets to the wall and have 17 foot length. I just fill it up and weight the wood until it doesn't want to float anymore. I also use it to pre-soak ribs before they go in the steamer on the w/c restorations I do.

 

[TheIndian]

Mounted on a wall in my shop is two sections of 4" eavestrough that is sealed so I can soak rails or whatever I need either before steaming or just for a good soak. I mounted L brackets to the wall and have 17 foot length. I just fill it up and weight the wood until it doesn't want to float anymore. I also use it to pre-soak ribs before they go in the steamer on the w/c restorations I do.

That great Mihon09...I might have to do the same thing in the future. Must require a good amount of oil I'm guessing.

 

[Guest]

Mounted on a wall in my shop is two sections of 4" eavestrough that is sealed so I can soak rails or whatever I need either before steaming or just for a good soak. I mounted L brackets to the wall and have 17 foot length. I just fill it up and weight the wood until it doesn't want to float anymore. I also use it to pre-soak ribs before they go in the steamer on the w/c restorations I do.

Karin, thank you. I have never done any steam bending, but I have been puzzled about the procedural technique of steam bending and oiling gunwales.

I could see steam bending the wood gunwales and putting them on wet-noodle pliable to accommodate recurved stems, but I couldn’t see a way to oil the undersides without removing the gunwales from the boat, oiling them and then reattaching, with the impossible hope that I would precisely hit every existing hole along the hull’s sheerline when reattaching them, and praying that the wood retained enough shape/curve “memory” to go back in place without brute force.

If I am following this correctly, you submerge the gunwales in oil first, and then steam bend them? Whoda thunk it, that makes sense.

If that is the procedure how long do you soak them in the oil filled gutter section?

And, how much oil does it take to submerge the gunwales. If it takes a gallon or two of oil to fill 17 feet of gutter trough what do you use as an oil or oil mixture? Can you pour off and re-use the oil?

I take it you use those gutter troughs both to oil soak and then pre-soak (water) the gunwales prior to steaming. Oil soak first, then pre-soak in water prior to steam bending?

Seriously, I don’t know what I don’t know about steam bending wood gunwales, but it is time to learn. Do tell.

 

[TheIndian]

Well thanks for all your help everyone. It all done and only I know where the mistakes are . One additional job I want to do is replace the painters actually.
Haven't paddled it yet...am hoping to take it to Lake Lila for it's maiden voyage, just hoping an intestinal issue will settle down first.
Anxious to paddle!
(trying to post some pics...only one seems to be cooperating so far)