What should I use, metal or wood?

I would like to build a small flat-bottom boat. I want something light enough that two people can lift to the top of a 4 runner. I would use this boat for fishing and goose hunting. I think it needs to be 12' X 4' or smaller. I would like to be able to put a small trolling motor on it and also ores.

Anyway, I was wondering if I should build it from plywood/epoxy or go with metal/aluminum. I don't know that much about welding, but my dad has a tig he would let me use. Is this too big of a project for a beginner? Also, I am pretty sure I could build a wood boat for under two hundred. How much would a metal boat cost?

Thanks,

Aaron

 

Buy a kit for a lapstrake dinghy. I think you'll spend around $500 anyway. You could probably find a solid used dinghy or tin boat for that price. If you only have $200 to spend, the classifieds in your regional paper are probably your best bet.

 

aluminum dingy

MalawiMD, the boat you're describing might be fine built from aluminum but it would be a vertical learning curve to build it with your Dad's TIG torch and 0.60" or 0.80" aluminum.

Manufacturers regularly build this size from alloy sheets but its not common to see them welded because welding this thin material is not for the new found welder. Riveting is how most of the very light aluminum boats are built because the welding aspect requires skills that cost too much to sustain when a rivet will suffice.
A WoodEpoxyStaturationTechnique (WEST) system "wooden" boat will be much more in reach for the newer boat builder. Avoid the epoxy on your skin and there is little to fault this method which has no arc or spark and a very much more manageable learning curve.
A bottle of Argon (for the TIG torch) will cost more than the you want to pay and if you've never welded, especially TIG welded, you'd need 100's of hours practice to tack-up the dink you're describing.

Go with wood, wire, and glue and you'll be in the water before you could produce a decent TIG bead on 0.60" sheet.

Cheers,
kmorin

 

Thanks kmorin! That is what I will do.

 

While welding is a high skill riveting is cheap and really easy to learn.

About an hour and you can do a pro job , no sweat .

Your health might be a concern , Epoxies (the BEST glue) is not kind to humans .

Aluminum has no health problems and can be far lighter than a same sixed plywood boat, as well as taking abuse (drag it on the beach , up on a dock or drop it from the roofrack) better.

Still its your choice,have fun!!

FAST FRED

 

Riveting

Fast Fred,
I agree riveting itself is easy to learn and with the correct anvil wt and air setting 'riveting' (peening or bucking up) is easy for the beginner to get good consistant results. But some of the work I've done on hulls is somewhat like aircraft work, super-exact sheet edge layout, Kleeco's to hold the drill pattern in place prior to populating rivets and, in the cases of hulls with some shape (orange peel at the bow), the work to make a stem or keel V blank to rivet on; is serious sheet metal forming.

I know that all the coal tar glops (epoxies) are skin sensitizers and not good to inhale, but with rubber gloves and a breather (half-face North or equiv.) I think first-off boats are easier, by far, in stitch-&-glue and plywood. Replacing a rivet or twenty in an existing boat or aluminum camper shell is one job, but I'm still convinced that the work to completely build a boat using rivets would be daunting for the novice builder. The goop method, with fiberglass taped seams, looks like a much easier project than finding a press brake with rounded nose bars to form the chine, keel, and sheer corner bend strips used in small riveted skiffs and john-boats.

I agree that the aluminum boat would be a better boat over the long haul, but I believe it would take considerably more effort to come by.

Cheers,
kmorin

 

This gent was looking for a "Flat Bottomed" boat ., which will be curved , but not shaped (no compound curves as with ply) so should be quite EZ to do.

An added advantage (if one has enough Cleekos) is the boat can be almost fully assembled before riveting , so any sub standard part can be replaced.

With goop epoxy the hull will usually be far heavier , and will need a complete start over should some early parts not be up to snuff.

Thats why Ho Jo has all those flavors , something for everyone!

FAST FRED

 

riveted boat

Fast Fred, even to build a riveted garvey, john boat, or pram I'd expect a chine curved upward in the forward 1/4 of the hull. This curved (profile view) angle stock used as a "chine log" to rivet the bottom and the topsides together would be a lot of effort wouldn't it?

Once the angle is formed with a bull nose press brake or sheet fold the angle would have to be formed around a mandrel for the shape of the chine's profile in elevation. Next it would have to be held temporarily (completely secure) while it was drilled and Kleeco'd with both sides and bottom in place as well as the gasket material. All this implies to me, that a full frame (building jig) would have to be built to hold all the overlaps while being drilled, Kl'co'd and then bucked up?

That sure does seem like a lot of work for a one-off 12'er. I can understand that a factory with all the overhead presumed like jigs, forming machinery, sheers, brakes and all would make short work of this little shape. But the home builder would find this no small investment to build the same boat once.

In 3 or 4 mm Okume ply the boat will be easy (messy and smelly- granted) to tack up with wire, glop on the smearing paste and sand off smooth. Add some decent enamel paint and you're off to the lake. (Wooden Boat mag has articles about 'weekend' skiffs for the family to build)

If MalawiMD were going into biz making small car toppers I'd buy into a riveting operation but I believe it would take nearly 10 times as long one-off. Once done - the phosphoric acid wash and zinc chromate rinse/primer to get ready for top coat would be more effort than the entire plywood and paste version and more toxic too.

I'd stick with the easier method for this boat -sheet metal is the better end product but the cost/time/effort investment will make a half dozen in wood/epoxy.

Cheers,
kmorin