8' Jon boat

[bobmwsc]

Hi everyone - I'm new to the forums and just wanted to make my first post. I'm also pretty new to boats as well so forgive me if I use the wron terminology from time to time. I'd been looking all summer long for a way to get my kids out on the water (just to do a little fishing) and then I remembered an old Jon boat that my dad had stashed behind his shed. To be honest - this little boat has seen better days. It was out behind his shed for at least 15 years when he got it free from a buddy of his. I have no idea the make or age of the boat. It's pretty beat up on the outside but it floats and my son (4) is very excited about it (my 6 y/o daughter couldn't care less). The boat lived a rough life before my dad got it and he'd actually never used it until we took it out 2 weeks ago. I just really wanted to see if it would float. There is a good size repair on the bottom - extending about an inch up the side. The weld is rough but it's watertight.

My project right now is replacing the wood on the transom. I acquired a 1987 Johnson 4hp motor that I hope will work well on the boat. There was some old plywood that definitely wasn't marine grade or even exterior grade in the rear. It literally crumbled in my hands when I went to take it out. I thought about replacing it wit a piece of treated plywood but since it wont see more than occasional use and since it's tiny and light and can be stored in the garage or the basement I picked up a pine stair tread. It's 1" thick and fits perfectly under the lip of the transom. Today I cut it and fitted it, drilled the holes, and it's getting a few coats of some spar urethane to hopefully protect it from some of the elements. I'll keep this thread updated as I make little improvements to the boat.

Here it is!


Only markings on the boat - plate is riveted to the front


Repair (outside) - I've been trying to build up around it with some JBWeld to smooth it out a little


Repair (inside) - who drilled all those holes?


Old transom wood


New transom wood - first fitting

 

[bobmwsc]

The motor I got is a 1987 Johnson 4hp. I got it from a from a freecycle website and wasn't exactly sure what to expect. To my surprise it came with the fuel tank and line and started on the second pull! Model # BJ4RCUD

 

[Dark3]

Wow, killer deal on the motor!

 

[bobmwsc]

Dark3 » 04 Sep 2014, 15:00[/url]"]Wow, killer deal on the motor!

Thanks. Is it a decent motor? I can't find any documentation online for this engine. The previous owner said it was in storage for a few years before they gave it to me. Any precautions I should take before running it on the boat?

 

[fool4fish1226]

bobmwsc » Today, 15:23[/url]"]

Dark3 » 04 Sep 2014, 15:00[/url]"]Wow, killer deal on the motor!

Thanks. Is it a decent motor? I can't find any documentation online for this engine. The previous owner said it was in storage for a few years before they gave it to me. Any precautions I should take before running it on the boat?

As for the motor I would give it a good look over (check for cracked fuel lines etc) and then give it a basic tune up (plug, wire, impeller, etc). You made a good decision not using treated wood. Treated wood and aluminum do not mix well the treated wood will eat up the boat real quick. Just keep you mods to a minimum with that size boat. I would not recommend any decks or raised seats and make your kids wear PDFs. Other then that enjoy the time on the water with the family. :beer:

P.S. :WELCOME:

 

[onthewater102]

That might be an air cooled motor - if so there won't be an impeller. If it runs well than so much the better, plugs, wires, fuel lines, all easy to inspect - might want to clean the carb in the off season.

 

[fool4fish1226]

onthewater102 » 8 minutes ago[/url]"]That might be an air cooled motor - if so there won't be an impeller. If it runs well than so much the better, plugs, wires, fuel lines, all easy to inspect - might want to clean the carb in the off season.

+1 on the carb cleaning also

 

[lckstckn2smknbrls]

Where do you plan on using the boat? If it's on a private lake your fine if it's on public waters your going to need to register the boat. Do you have the title? Do you need a title in your state?

 

[bobmwsc]

Where do you plan on using the boat? If it's on a private lake your fine if it's on public waters your going to need to register the boat. Do you have the title? Do you need a title in your state?

I live in Massachusetts where I believe they changed it (since I was a kid and my dad had a 12' aluminum vhull) so any sized boat with any motor, gas or electric, needs to be registered to be used in public - and no I don't have a title and I don't know if I need one. Not sure where to start with this.

 

[bobmwsc]

I just a few questions to go along with my posts...

1.) To secure the new transom wood - stainless steel bolts? I've heard various stories about various metals reacting with the aluminum and the best info that I could find was that if aluminum rivets aren't available - which they aren't - that stainless is the best option.

2.) Any ideal what the load capacity of an 8' Jon boat is? It's about 2' 7" wide on the floor and 3' 7" wide at the top. I had my dad, myself, my son and some minimal gear and it seemed to sit pretty well and was stable. I'd say the scale would have been right around 450lbs. Not sure if this is pushing the limits or not.

3.) When I get to this point - paint. Self etching primer and rattle can Rustoleum OK for a few years? I'll sand down/scuff up what's on there before respraying.

 

[onthewater102]

So you're over in my corner of the country - what part of MA are you in? I'm over on the NY line half way down CT.

As for your three questions:

1.) Stainless is the way to go - give the holes a coating of marine epoxy to be sure they stay sealed up.

2.) Absolute capacity is a function of displacement, water weighs ~62lbs per cubic foot. Every cubic foot of water you displace will support 62lbs, so if you've got a boat that's 3' wide (2'7" tapering to 3'7" rough approx. avg. ~ 3') and 8' long, so for every 1" of water depth the boat displaces will support 125lbs. Include in your total weight the weight of the boat (probably about 80 ~ 100 lbs) so if you load 450lbs worth of gear plus the weight of the boat your keel will be roughly 4" to 5" deep in the water. Subtract that 5" from the height of your sides and you'll know how much boat you'll have above the waterline (freeboard). This will differ from the boats rated capacity, which is usually approximately 20% of the weight required to swamp the boat.

3.) Self etching primer is what you'll need, just make sure it bonds to aluminum and that after you scuff everything up you clean it down with denatured alcohol or something that will quickly cut through any oily contaminates on the surface.

 

[bobmwsc]

onthewater102 - I'm over in central MA in West Boylston - right outside of Worcester.

Also - thanks for the answers. If I can make it over to my parents house today I'll measure the height of the sides. When we took it out we didn't have a motor attached so that will add some more weight - probably about 50-60 lbs including fuel.

For the marine epoxy to seal the stainless hardware - 3m 5200? I've seen they sell a small tube at the Home Depot for around $6 which should be more than enough for this project.

 

[onthewater102]

No - 5200 isn't epoxy, and while it's popular around here if you read its material specs from 3M its only recommended on primed metals. A drill hole through the transom will have exposed aluminum.

I believe you can get 2 part marine epoxy at the big-box stores too - if not Wally-World carries it. It's much less expensive than 5200 but takes 24 hours to fully cure and it bonds to aluminum.

Be careful to read the material specs on any adhesive you try to use on aluminum if you want a permanent fix.

 

[bobmwsc]

I'm going to be reusing the existing rivet holes. Would I be all set with the 5200 if I prime inside them with the self etching primer? The Walmart in town carries the JBWeld Marine 2 part epoxy but I wasn't sure that I want a totally permanent bond.

 

[onthewater102]

I should think so - you'll be following 3M's instructions at that point... The 5200 is still going to solidify and serve as a gasket even if it ceases to hold, and it will be much easier to remove than epoxy if you're not thinking this is permanent.

 

[bobmwsc]

drilled, stained and several coats of spar urethane



test fit - I wont attach it permanently until the boat is painted



I need to pick up slightly smaller washers for the top. There was also a battered piece of sheet metal that had been affixed to the inside so where the motor mounts it wouldn't wreck the wood. I'm guessing it was steel because of the corrosion where it was touching the aluminum. I'll pick up a small sheet of sheet aluminum to replace it.

 

[bobmwsc]

So i started stripping paint off the boat - spent about an hour and got about 1/3 of the bottom of the boat done. There are still some specks of paint that I'll probably use some aircraft stripper on after. I've been using one of the wire cup brushes and it does a pretty good job. It's leaving a nice swirl pattern in the aluminum. Any tips or trick for easier paint removal? I tried the aircraft stripper alone but it would work very well in one area and not touch the paint in another spot.

 

[Attwanl]

My tin didn't have any numbers ether.....in fl they asked if it was a pre 70's and after a notarized bill of sale from previous owner and that it had never been registered before. They issued me a vin number for it.
Same with my trailer, it was about 4 trailer boned and put together so they issued me a vin for a home made trailer.
Don't know how it is where your at, but hope this info helps

 

[bobmwsc]

I acquired another motor yesterday - a 3.3 hp Mercury - model number on sticker is 3G9. I'm not sure of the year but it's is in great shape. I took off the cowl and the inside was spotless. The owner stated that the "it runs but needs lower gear unit internal cleaning" - his words, not mine. I tested it out this morning and the motor started right up. Well, it started right up after I figured out what the clip attached to the lanyard was. In the off season I'll change out the gearcase oil. Is there some sort of flush I can do on the lower end before adding new oil? I never took it out of neutral while running because of what the previous owner stated but before I added fuel I put it in gear then pulled the starter rope and the prop turned freely and without resistance. The only other issue is the spark plug boot has a small crack so if I can find a replacement wire I'll do that as well.

I'm going to have to run both on the boat when it's ready for the water and see what is a better combination of weight vs power. The Mercury seems to be a little lighter and quieter than the Johnson - but I don't think either will have an issue pushing an 8' boat. Any recommendations?

On the plus side an owners manual for a Mercury motor is a lot easier to acquire than one for a Johnson.

 

[bobmwsc]

It's been a while since I posted and I really haven't had anytime to work on the Jon Boat beyond removing all the paint. Once the 47 feet of snow melt outside I'll finish rebuilding it.

Yesterday I did, however, find out some info that may be useful to others if they need to register an old boat without a title in Massachusetts. I was at the "Boat, Recreation Vehicle & Snowmobile Registration Bureau" in Worcester yesterday to transfer a title to a new to me 1989 Bayliner Capri 1750. I asked about the process for registering an old, untitled boat. The woman that I spoke with stated that I needed a notarized statement of facts regarding the boat: how it was acquired, reason for lack of identification numbers. With the statement of facts and the registration form they would be able to issue a registration number for it. For the 8' Jon it would be $44 for 2 years. The workers at that branch were really helpful!