Prospector re-glass and repair

Nutkin

Canoodler
Hi all, Thanks for being here. I've got a question or two about a repair job I have begun.

About 15 years ago I built the Chestnut Prospector from Canoecraft and it has been in storage for the past several years while I directed my attention to restoring an 1850 cottage. The canoe is stripped with Western Red Cedar and has Ash gunwales and decks.

At one point it was left sitting, upturned, on the ground for several months. The ash at the ends began to decay and both gunwales showed signs of spalting. (incipient rot) The other major problem with it is when I built it it was my first attempt at fiberglassing and I was at the bottom of a steep learning curve. IT was really too hot and humid a day to be glassing, for starters. Liberal amounts of sweat dripped into the epoxy, along with air, and with the heat it began kicking too quickly, so the result was a very milky complexion in spots.

Yesterday I stripped the glass from the exterior of the canoe and now I am debating whether to re-do the gunwales. In order to disguise the spalting I stained them dark brown, which I hate only slightly less than the spalting. The gunwales are epoxied and screwed on with brass screws that are plugged. Gettign the screws out is no problem, but I wonder about how tough it will be to remove the gunwales from the hull. They are on top of the glass so I'm guessing that either the glass/cedar bond will fail first before the glass/ash bond will. Is there any trick to taking them off? Deadblow mallet?

I plan on removing the outwales, sanding the outer hull, filling the few tear-outs from glass removal, re-glassing the outside, then flipping over the canoe and removing the inwales, decks, and glass, before sanding and re-glassing the inside.

Any thoughts or advice are appreciated.
 
Yep, that's one of the best reasons never to glue ash gunwales to a hull. A mallet sounds pretty dangerous and the grain strength of the cedar is likely less than that of the ash, so it might tear first. If the plan is to remove and replace the glass, I think I'd take a sabre saw to the gunwales and cut them down, pretty close to the hull. Then I might get out a plane and shave them down until there is only about 1/8" or less of gunwale remaining, glued to the hull. At that point, they would probably be thin enough that you can heat up the little strip of remaining gunwale and the glass under it with a heat gun, soften it and scrape them both off.

Or....once it's reduced to a thin strip, you could sand it off if you're careful. Glass is harder than ash by a little bit, so you have a possibility of sanding off the ash and stopping before you go through the glass and into the cedar.
 
Thanks Todd.
Yep, that's one of the best reasons never to glue ash gunwales to a hull.
Sadder but wiser here. The jigsaw is a great idea. I'll have another crack at it next Friday and let you know how it goes.
 
Will post pictures of the job so far tonight. In the meantime I have a dilemma about the gunwales.

I am nearly ready to remove the punky ash gunwales, but I want to have the replacements ready to install first. I looked over what I have available and in my pile of wood I've got cherry, birch, maple, cedar, & white oak. Nothing long enough w/o having to scarf.

My first choice would be Mahagony but I haven't got any and the prices are insane right now for Honduran.
While Oak would be strong and rot proof, I'd rather not deal with filling the grain, and I'm not wild about the weight.
Birch, it seems is as rot prone as Maple, they both stain easily and begin to show spalting right away, so that leaves the Cherry and Cedar.

I'm tempted to use the cedar for lightness but I'm concerned about its strength/durability, especially as I use the scuppers for lashing.

Anyone have other ideas or opinions? Thanks in advance.
 
Cherry will work if it's reasonably free of grain run-out. It's strong enough, holds fasteners well and finishes up nicely. The trick is finding long hunks with reasonably straight grain. Cedar gunwales really tend to get beat up easily, so it's not a particularly good choice. The same is true of almost any softwood outwale (fir, pine, spruce, hemlock, etc.) though they can often work fine for inwales. Top of my head, I think white oak only weighs about 10% more than the ash you have on there now, so in terms of strength and all-around durability it's probably the best of the bunch. One of the easiest ways to fill the grain is with epoxy resin. You're not trying to coat it, you scrape the resin into the pores using a plastic scraper (an old credit card works pretty well). After it cures, you sand the surface clean and proceed to varnish and/or stain if desired.

With any of these woods though, it's important to understand that these boats need inside storage. There is no wood species and there is no wood finish that you can leave out in the weather for extended periods that won't suffer for it. They will all weather and deteriorate (along with the epoxy/fiberglass on the hull) and it's simply a matter of how long a particular piece of canoe will last before that happens. The old, weather-beaten, rotted canoes that you see being restored didn't usually get that way from use, they got that way from poor storage. So the question of what will weather-out or rot faster, a birch canoe gunwale or a mahogany one really shouldn't be part of the equation. With proper treatment, thay can both last a very long time. Without proper treatment, they'll both be toast in just a few seasons.
 
That's exactly what happened to mine. About a year after I built it I got married and moved to a new state. Our new place didn't have any storage and a friend offered to let me keep it in his back yard on horses. What was supposed to be a month or two, turned into a year and at some point the canoe was no longer on horses any longer. The worst damage was to the stems and the first five inches of the gunwales.

I finished sanding off all the old epoxy a few minutes ago and my observations about that first glassing job of mine are that it was a train wreck. Spots were far too thick (maybe the glass floated?) other spots were barely adhered to the wood, the day I had chosen to glass was hot and humid and I dripped sweat into the wet epoxy, very cloudy. So it is great that I removed all that.

In the process of removing the glass there were a few tear-outs and I also noticed, in spots, the lip of the cove has splintered away. I plan to fill the more egregious tear-outs with cedar dust and epoxy, but I wonder about the hairline splinters. I'm thinking the epoxy should fill them.

So, considering your excellent point about storage and care, I ought to be ok with the birch since I have 10 footers, the oak would require an extra scarf joint and is old growth, tight grain, highly figured stock leftover from a furniture job that would be a shame to make into gunwales.
 

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Suggestions for filling/fairing gouges and tear-outs

I'm nearly at the point where I need to fill the tear-outs in the hull before I fair it. I want to avoid the sawdust/glue paste or sawdust epoxy paste since they tend to sand less readily than the surrounding wood. Durham's rock hard putty? West system filler? I've never used it, but it sounds like it sands well. There are two colors apparently, a reddish one and a beige one. The reddish one looks a little like bondo. The gouges are on the underside so won't be seen except by scrutinous fish.

As usual, opinions are appreciated.
 
Yes, wood dust tends to make filler that's probably twice as hard as cedar and difficult to sand without tearing up the wood around it first. It also goes much darker when resin saturated, so you would probably need dust from something like birch or pine to match cedar. The WEST 407 is mostly phenolic microballoons, so it has the typical reddish-brown (slightly burgundy) color that most phenolic resin items have (like a lot of old circuit boards). It sands reasonably easily and isn't too bad to sand fair on cedar. The 410 Microlight filler is more tan in color, sands even easier and might be a better choice in terms of easy fairing and color match if your hull is a lighter shade of cedar. You can wipe down a section of the bare wood hull with a damp cloth to see what color ithe wood will actually go when resin coated. Either one would work, but the 410 might match better and sand a little easier. Or....you could buy a small container of both and mix them as needed to possibly get a more accurate color match.

Be advised that in order to make good filler with these you need a generous pile of filler and a rather small amount of resin. Usually a single shot from the resin and hardener pumps and 6-8 heaping tablespoons (or more) of filler will make a batch that will do a fair bit of filling. Mixing much more than that can sometimes mean that it hardens in the pot before you get a chance to apply it. It pays to do a small test batch first. Mix in enough filler so that it will stand on a surface and not sag and pool. Then come back in 1/2 hour and make sure it's stayed that way and didn't flow out into a puddle. If it flowed, increase the amount of filler you add until it won't and keep track of the ratio that works so that you can duplicate it on every batch.

Once you know the ratio, mix a small batch of just resin and hardener. Take a small cheap brush (like an acid brush from a hardware store - $.25) and brush a light coat of the resin into the gouge in the hull. You're trying to pre-coat the wood, not fill the hole. This improves the bond and keeps the wood from sucking resin out of your filler mixture. As soon as that's done (while the resin pre-coat is still "wet") mix and apply your fill, leaving it standing a bit proud of the surface. Let it all harden, sand it smooth and that spot is ready for glassing.
 
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Thanks Todd.
I'm going to try a mix for the areas that will be visible and see how close I can match the color.

Here is a status report on the reglassing:
Outwales removed with a little damage to the sheer strip, mostly from backing out deck screws. This can all be filled and will be covered by new gunwales so I am not worried about cosmetics or structure.
Initially I took a surgical approach and drilled out the plugs, then backed out the screws. After a while I realized I just needed to break out my big chisel and in two swipes revealed each screw head. Most of them backed out ok, a few needed the needle nosed vice grips.

after all the screws were out I ripped as close to the planks as possible with a jigsaw, then went after it with a heat gun and a heavy spatula like scraper made by hyde. It looks like a very sharp grill spatula. I used the blade as a heat shield to prevent the heatgun from blackening the cedar, the sharp edge worked under the glass and helped lift the remainder of the ash. In most parts all that remained was about 1/16th or an 1/8th.

Luckily, my epoxy job left a lot to be desired and it all came off rather easily with minimal wood damage even when I had to just tear the gunwale off.

Next step is to fill/fair and sand. Then I'll glass the outside and replace the outwales before removing the interior gunwales, decks, and glass.

Note the punkyness to the stem and partial de-lamming. I am thinking of putting a Dutchman in to replace the top inch or two of the stem.

The inside of the canoe shows the worst clouding from all the sweat I dripped into the job. It was about 95 degrees and 1100% humidity when I did the glassing. 15 years later and I am really glad to be repairing that heinous blight.
 

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