Has anyone ever built Atkin's River Rat. I have an idea for repurposing the hull.

[DanSkorupka]

I am considering repurposing the hull form of River Rat 22 scow as a jack of all trades middleweight utility. I envision it as a homebuildable alternative to the huge v bow aluminum jon boats that are very common in many areas of the US.

The shape of the hull itself would be unchanged and the use of ply on frame construction would be retained.

the lines are from http://www.atkinboatplans.com/Oar/RiverRat.html

The changes I am considering are:

1. Get rid of the huge cabin. Leave a head with some privacy. kitchen, beds, full roof: gone. Semi permanent tent optional.
2. With the weight of the cabin gone, increase scantlings dramatically. The original fishy sounding 3/8 bottom and 1/4 inch topsides will both be replaced with 3/4 inch marine ply or good mdo. Oak frames possibly replaced with longleaf pine or clear douglas-fir for reasons of cost.
3. Knowing it will rarely see open waters, and spend most of its time in fresh water and in or near harbors, an internal motor well may not be entirely necessary. To make more room inside the motor will be moved to the transom and a splash well used.

For now this is just a thought exercise, and I do not currently intend to build. If I ever build I would likely power with a 1960s era evinrude 18 for financial reasons, namely I got one off craigslist for my 21st birthday and I don't have enough money for a newer motor. If I had an unlimited budget I would likely try to find a Yamaha 40hp two stroke based on their popularity with commercial fishermen.

[thud]

That looks like a great stable boat.
I like your idea of skipping the Cabin top etc. Saving lots of weight is always a good thing.

Weight to HP ratio...I doubt if your 18 will get you beyond 10-12 Mph. If you try for any more speed with it, the prop will churn up a lot of water and waste a lot of fuel.
However for Trolling that 18 should be perfect!

If that slow speed is OK with you, your in good shape already.
The 10 Mph ride is something I've had a lot of in my past.
For that kind of adventure you'll want a Helm, not a Tiller. Boredom sets in after a few minutes and you need the Coffee Cup holder, a place for the Peanuts and snacks etc.

Invent a Collapsible top that don't get in the way when it's collapsed.
Tuck the Head in under the front of the Helm. The Girls like a little privacy there.

Another idea to make the whole boat a big floating platform, put the Helm right back over that motor, and make the Deck all one big level walking around area.
Kids can fish safely that way and you can build a seat stanchion into the Deck if your passengers feel the need for a seat instead of sitting on the top of the sides.

As far as the structure of the boat goes.
Oak aint necessary but nothing holds a Screw like Oak.
You can keep the boat dry when not in use. Or dry it out reasonably quickly after a trip, almost any wood will be good.

Board n' Batton Bottom and Decking. AKA Hill Billy Siding or Barn Construction.
I wish I could draw pictures with a 3-D program to show you what I'm thinking.
Instead of Plywood for the bottom and decking, use some 1/2 Inch Pine boards about 6" or 8" wide. Plan on smaller strips over the joints between the Longitudinal boards, called Battens, which will run the length of the boat's bottom and become 'rubbing strips' for beaching, and also little Keels to keep your course for you in a wind.
With a Board n' Batten bottom you wont need that Keel piece back by the motor.

3/8's Ply is also good. It'll last a long time and it is easily replaceable. Make sure you Sealer,Primer,Paint with the right stuff though. Use PL (poly sumpinorother) not PE for glue.
I personally wont fiberglass wood. It makes it expensive, heavy and really nasty looking failures.

Plywood is fine for the Sides and even the tops of the Sides for seats and shelves beneath the Tops of the sides.
Seal all the edges of the Plywood with some kind of Wood Veneer and the PL Glue.
Drill drain holes in all your shelving and stowage.

Find scraps of Pine at new House Construction sites, Dumpsters etc. Start saving that stuff now. That becomes your Corner pieces, struts, ribs, and gussets and all kinds of Etc.

You can do a little Engineering with other things too. Like a Shelf area for the Gas tanks. Plumb long lines to the motor so you can switch tanks with out a lot of fuss.

[DanSkorupka]

Regarding top speed

10-12 Mph. If you try for any more speed with it, the prop will churn up a lot of water and waste a lot of fuel.

It is not a pure displacement hull and will plane given enough oomph. A displacement hull would have a huge amount of chine rocker aft and substantial deadrise aft.

The lines show more a semi planing to planing hull. It has keel rocker but not chine rocker and there is only a little deadrise near the stern. The original claim from the designer was 17 mph with 25 hp using the light scantlings and including the full cabin. There is a link above. 10 to 12 mph does sound like a good cruising speed and it seems to be a shape that will not nose up and plow excessively in the low planing range (I am not an expert on these things though).

Your advice on glassing is very valuable. I have learned from others mistakes. I personally met someone at a pond popular with wealthy tourists due to its association with a famous author, who paid over $10 per board foot for clear full length old growth cedar strips to make a canoe and then slathered the bottom with goo and itchfibre (didn't even do a good job of it) and epoxied the inside as well. After a few trips he had bad leaks. The resin cracked, water got in, and went in the bilge. He said he had learned his lesson and would remove all the glass and plastic. I told him to do it fast because the coating holds water in as well as out and it would be a couple more weeks of over 90f outside. He cringed when the words "dry rot" came out of my mouth. He seemed to also be unnerved that he had heard this from a then teenager. I may be young but I know what I'm doing.

[Breakaway]

I'd think you' want to consider whether the boat will sit on her lines with the cabin weight gone from the bow and the engine weight moved further aft. Just saying to consider it.

Kevin

[thud]

"I may be young but I know what I'm doing"
And you are in with a lot of guys with a lot of experience here as well.

I said "Dry Rot" to an old Boat builder one time.
He lit into me with wit n' humor.
It's ROT.
It takes three things to have Rot in your wood boat.
Warm conditions, no air circulation and Moisture.

He had some other witticisms. "If we didn't have Wood Rot, the whole Earth would be covered 60 feet deep in Logs, chips and Sawdust".
That was a good one, I'd never given Rot a thought one way or the other.

I have been intending to build a 12' Jon for my pleasure for the last three years now. Don't know if it will happen.
My plan is to use the Board n' Batten bottom. No keel except for the Battens which will be Oak.
Just a little 'Rocker' about 6" in 12'.
Hardly any side to side (rocker) almost a flat bottom side to side.

Do it when you want to. Do be rushed. Buy any old boat to fish in, while you build your good boat.

[JimD]

Here's one designed as a work boat: http://www.boatplans.dk/pictures.asp?id=14

[JimD]

Something of a houseboat without the house, and there are a few other choices around, ie, from Bateau

[thud]

Great drawings. I wish I could do that.

The "Next to the last" one (Center Console) has all the right moves.
It's heavy enough the Helm could be further aft for me. I like all that Deck to move around in.
It'd be my choice for River Fishing.

I turned into a wind without enough weight up front, and the wind stood the boat upright. Somehow I didn't go over backwards but I learned that day about loading and spacing.