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Can Anyone Measure Inwale/Outwale Dimensions on a MR Explorer?

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A Royalex MR Explorer hull turned up for sale less than 1500 feet from my house, sans gunnels. But for $100 I couldn't say "no."

Now I need to fashion some new wood ones. Curious what the original MR gunnels sizing was. Looking for width and thickness of original wood gunnels. Thanks!.

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Mine is in deep storage but I should be able to get to the gunnels tomorrow. One of them is the original from 1991, the other was replaced in 2001 but as I recall (been a while since I've used it) the replacement was a perfect match.

My Explorer has a similar "kink" in the hull only it's larger and created a crack where the gunnel snapped (REALLY hard impact with a giant boulder), almost the same spot as it's the weak area when paddled solo from the bow seat and Mad River's "thwartless" design.
 
Mine is in deep storage but I should be able to get to the gunnels tomorrow. One of them is the original from 1991, the other was replaced in 2001 but as I recall (been a while since I've used it) the replacement was a perfect match.

My Explorer has a similar "kink" in the hull only it's larger and created a crack where the gunnel snapped (REALLY hard impact with a giant boulder), almost the same spot as it's the weak area when paddled solo from the bow seat and Mad River's "thwartless" design.

Thanks, recped. Yes, the hull is in great shape except for the kink that you noticed. Some superficial scratches in the bottom but nothing through the outer vinyl and the stems are in remarkable shape. This is going to be set up as a solo and may get an extra thwart or two.
 
We paddle a 1979 MR Royalex Explorer which we inherited from my Dad, who bought it new. It still has original ash gunnels. The out wales measure 7/8 inch wide by 5/8 inch tall. the in wales are 5/8 inch wide by 1 inch tall.

Nice score on a versatile hull! We love ours. I'm learning to pole in it now.
 
Rick, for rebuilder purposes, if you would, what are the sheerline-to-sheerline (not outwale) dimensions at the yoke, and at the back (or front) of each seat?

I could measure, but both of the Explorers to which I still have access, one glass, one RX, were rebuilt and drawn in a touch amidships.
 
It's dark in that garage and infested with cobwebs!

Best I could come up with (in millimetres) :

Outwale #1 - 21 x 15
Inwale #1 - 23 x 15

Outwale #2 - 24 x 16
Inwale #2 - 21 x 16

I wish I had a proper measuring caliper but I don't so these measurements came from transferring marks from a piece of scrap wood, probably not entirely accurate but pretty close. In use and to the naked eye they always appeared to me be the same on each side (one original, one replacement), both sides have had some treatment in the past with steel wool so there is a chance that could account for a mm or so difference along with my not 100% accurate measuring technique.
 
I had my 1992 17' MR Revelation/explorer out on the river yesterday and took measurements. I know these gunwales are original and are the same as a friends RX 16' explorer from roughly the same year. The height and width of inside and outside Wales are the same: 21/32" high by 13/16" wide. MR used 1-1/2" ss sheet metal screws instead of wood screws for some reason, maybe theyre .005 cents less expensive?. As you know, all the screws are driven from the inside except for the last few towards the ends. This is why the ouwales need to be so wide. If I were to re rail one of these I would reduce the width of the ouwales by 1/4" or so and drive all the screws from the outside, then use 1-1/4" wood screws. This could save you a few pounds if that matters. Drilling and driving screws from the inside is a PITA and causes lots of frustration with stripped screws. Since you will likely be taking your time, you can also avoid drilling gunwale screw holes right on top of thwart and seat bolt holes. Apparently they didnt care about that at the factory. I would also take a little extra time and reconfigure the ugly MR decks that are screwed in to the top, almost as an afterthought. At least my decks are wood. It was another step down when they switched to plastic sheets for decks. Otherwise I really like mine! Take care, Mark Mark
 
I had my 1992 17' MR Revelation/explorer out on the river yesterday and took measurements. I know these gunwales are original and are the same as a friends RX 16' explorer from roughly the same year. The height and width of inside and outside Wales are the same: 21/32" high by 13/16" wide. MR used 1-1/2" ss sheet metal screws instead of wood screws for some reason, maybe theyre .005 cents less expensive?. As you know, all the screws are driven from the inside except for the last few towards the ends. This is why the ouwales need to be so wide. If I were to re rail one of these I would reduce the width of the ouwales by 1/4" or so and drive all the screws from the outside, then use 1-1/4" wood screws. This could save you a few pounds if that matters. Drilling and driving screws from the inside is a PITA and causes lots of frustration with stripped screws. Since you will likely be taking your time, you can also avoid drilling gunwale screw holes right on top of thwart and seat bolt holes. Apparently they didnt care about that at the factory. I would also take a little extra time and reconfigure the ugly MR decks that are screwed in to the top, almost as an afterthought. At least my decks are wood. It was another step down when they switched to plastic sheets for decks. Otherwise I really like mine! Take care, Mark Mark

Thanks for info Mark. 5/8 x 3/4 is the max I'd go and maybe 5/8 x 5/8 (with a little extra glued on where the seats will go. I will definitely drill/screw from the outside and I agree the MR wood decks plunked on top look terrible; I'll inset mine.
 
Here you go Mike!

The centerline of the carry thwart measures 35 inches at out side of hull (outer surface of Royalex).

The front of the stern seat is located 50.5 inches aft, and measures 23.25 inches.

The front of the bow seat is located 43.5 inches forward, and measures 26.5 inches.

I had noted and always thought peculiar, the gunwale dimensions on our Explorer. Thanks to Mark's post I now know why. It was all about manufacturing process. This site is awesome!

Rick
 
After Ricks post I went out and measured the max width of the 17' version and it's a whopping 37.25" from the outside of the royalex. I don't think this hull is just an upscaled explorer since it appears to have quite a bit of extra volume added towards the ends. It is a beast, and i dont know what it weighs with wood gunwales, but is about all I can handle to get it up on my shoulders. On the water it handles surprisingly well in rapids for being such a barge, and holds its own on the flat. Anybody travelling to Montana is welcome to borrow it for a river trip. Mark
 
The centerline of the carry thwart measures 35 inches at out side of hull (outer surface of Royalex).

The front of the stern seat is located 50.5 inches aft, and measures 23.25 inches.

The front of the bow seat is located 43.5 inches forward, and measures 26.5 inches.

Rick, thanks for the measurements; those dimensions are especially important when rebuilding a hull without gunwales if you want to keep it stock.

I’ve rebuilt three (maybe four?) MRC Explorers on which the wood gunwales were toast. No dis on Mad River, the Explorer is a great do-a-bit-of-everything canoe. Tripping, day paddling, flatwater, moving water, tandem, backwards solo, sailing, poling; I’m not sure there is a better all-around design for my varied purposes.

The Explorer was just a very popular canoe, and MRC started making them with wood gunwales in 1975. Wonder how many (tens of thousands?) of them MRC sold in 40-some years.

ALSG’s gunwale-less Explorer appears to be near pristine on the inside, just a vinyl skin wrinkle or two, no crumbly old kneeling pads or aged D-rings to scrape off, and the paddlers must have worn ballet slippers. If the outside is in equally good condition it couldn’t have seen much water time.

70+ lb Royalex Explorers are beyond my aging back’s weight bearing capacity, and the glass ones as well (speced 69lbs with wood gunwales, 65lbs with aluminum), but if I found a Explorer in KV, KH or KL (39lbs with aluminum gunwales!) in need of rebuild I would snap it up, and try not to beat it up.

I got curious and measured the distance at center on our RX Explorer. A bit under 34”; I single seat “soloized” that Explorer and drew the sheerline in a bit at center, planning to pulling it in 2” as I’ve done on other tandems. IIRC I stopped at a bit under an inch reduction because the (vinyl) gunwales were starting to take an inward cant on the wide flat bottoms, and I wanted the brightwork seated flush.

FWIW I’ve drawn in the gunwales up to 2” at center on several canoes, both RX and composite. Contrary to “conventional wisdom” that decrease had zero effect on the bottom or rocker. Two inches at center, tapering less towards the stems, across 192 inches of sheerline, isn’t enough to induce any change beyond adding a small touch of tumblehome.

(Eh, I drew one wide, center flared hull in 4 inches in total. Still no change in the bottom or rocker, but it put a lot of stress on the now sharpened chines. And, oops, radically altered the secondary stability)

Which brings up another Explorer measurement, Royalex vs composite. Not only is the catalog length speced different, so is the width:

Royalex – 16’, 35”
Composite – 16’ 4”, 34 ½”

The stern height is listed as different as well. Bow and stern are 22”/22” in RX, 22”/20” in composite.

I’m looking forward to seeing ALSG’s rebuild.
 
After Ricks post I went out and measured the max width of the 17' version and it's a whopping 37.25" from the outside of the royalex. I don't think this hull is just an upscaled explorer since it appears to have quite a bit of extra volume added towards the ends. It is a beast, and i dont know what it weighs with wood gunwales, but is about all I can handle to get it up on my shoulders.

I think MRC only made the Explorer 17 for a handful of years in the late 80’s/early 90’s.

Checking some old catalogs, the Explorer 17 specs at 17’ 2” long, 15” deep at center, 22” high stems.

The other catalog specs were all sorts of wrong. I looked in three different year’s catalogs; if the Explorer 17 was 27” wide I need a new tape measure. Gotta be a 37” typo, one that somehow stayed unchanged in each year’s listing.

And the Explorer 17 material is specified in each catalog as “Royalex Plus”, with the weight consistent, listed at. . . . . . .72lbs.

BWAHAHAHA, if that canoe weighs 72 lbs it must be the rare “Royalex Minus” version.

Makes me wonder if my early 90’s Explorer 16 or the ’89 I rebuilt for a friend are “Royalex Plus”. Mine has the plus weight at a solid 85 lbs, and his has to be close.
 
Hey Mike, you should know this. Is the Explorer 17 the same as the Revelation? It seems to be. Interesting that they had a royalex plus, mine seems to have that. I've lifted 75lb canoes and this one is noticeably heavier. Mark
 
Mine is also probably Royalex "plus", although I've never weighed it I'd definitely say it's 80_lbs.

My guess is that Royalex Plus is anything beefier than the stock sheets, In my explorer there is a noticeable "line" near the bow seat where it appears the Royalex sheet is thicker (out to the stem) than the centre section of the boat. My understanding was that Royalex sheets could be ordered to custom specs including differences in the thickness within a single sheet. I do not know if that extra comes from the foam layer, the inner layer or the outer layer
 
Mine is also probably Royalex "plus", although I've never weighed it I'd definitely say it's 80_lbs.

My guess is that Royalex Plus is anything beefier than the stock sheets, In my explorer there is a noticeable "line" near the bow seat where it appears the Royalex sheet is thicker (out to the stem) than the centre section of the boat. My understanding was that Royalex sheets could be ordered to custom specs including differences in the thickness within a single sheet. I do not know if that extra comes from the foam layer, the inner layer or the outer layer

Looking at my Explorer hull without gunnels, the Royalex is noticeably thicker from both stems back several inches.
 
Hey Mike, you should know this. Is the Explorer 17 the same as the Revelation? It seems to be. Interesting that they had a royalex plus, mine seems to have that. I've lifted 75lb canoes and this one is noticeably heavier. Mark

Explorer 17 v Revelation 17

Mark, I do not know. I owned a Revelation, and later the (re-badged?) the Freedom 17, and it seemed to carry width further forward than the Explorer 17, but I never compared them side by side.

MRC made the RX Explorer 17 from ’84 to 1991, and the Revelation 17 from 1992 to 2002. I think the Revelation was later re-badged as the Freedom 17 (2003 – 2008). Lotta things were getting corporate Freedom-ized in the early 2000’s (Freedom Solo. . . .Freedom Fries!)

The Explorer 17/Revelation 17 have essentially the same dimensions, with at most a slight difference or design tweak, maybe just outfitting changes or thwart width changes off the same mold.

The last catalog year for the Explorer 17:

https://web.archive.org/web/20130604030723/http://www.madrivercanoe.com/content/madrivercanoe.com/assets/page/archived_catalogs/MRC%201991a%20versatile.pdf

17’ 2” long
37” wide
15” deep
22” stems

The first catalog year for the Revelation:

https://web.archive.org/web/20130604033300/http://www.madrivercanoe.com/content/madrivercanoe.com/assets/page/archived_catalogs/MRC%201992a%20versatile.pdf

17’ long
37” wide
15” deep
24” bow stem, 23” stern.

Very similar design, with some wee tweaks, or perhaps just re-measures. The Revelation was listed at 78 or 79 lbs, but I never for a minute believed 72lbs for the Explorer 17.
 
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