New 4A032 Deck Over Build for my kiddos.....

[Salty Techsan]

OK... here she is.. about 98% complete anyway... only thing I haven't done is the black, non-skid on the deck.

Thanks to all of you that have taken the time to post your project detail as I never would have had the nerve to take on a project like this otherwise... I am a very novice welder, and had zero experience bending or shaping metal in any way, shape or form prior to this project. Starting out, I was flying pretty blind, and really wasn't sure if any of this would work, so went pretty crude on the hull.. I used whatever inexpensive materials I could get my hands on as I didn't want to have too much time and money in a project that may or may not actually work... surrisingly.. the hull turned out pretty decent, despite it being a fairly half arse effort.

Details....

Power - 4A032-4 Continental Teledyne.. purchased new, in crate, zero hours for $350 + shipping off ebay
Mods - I bored out the carb venturi to 9/16" (did get me about 200 RPM boost over stock), removed orig air cleaner (no notable performance difference), and removed the governor (no performance difference at all)
Hub - $119 hub made for the 4a032 from Arrow Prop (fit like a glove.. very happy with it)
Prop - Started with Ultra 3blade... started at 44", 12 degree pitch blocks.. would only make 2350 RPM.. dropped to 9 degree pitch blocks and got me to 2700rpm... shaved 5/8" off each blade... getting me down to 42 3/4" diameter, which is now making a consistent 2850 RPM with the 9 degree pitch blocks. Was hoping to get to 3000, but was scared to give up any more diameter. Might shave another 1/2" at some point..
Tach - Tiny Tach purchased from Bob at Ultra Prop
Lube - Royal Purple 10w30
Fuel - mainly running 100 octane Avgas b/c I know its ethanol free, and had heard that the ethenol stuff could cause issues with carb float on these motors.. have also run super with no notable perf difference.

Hull
9'6" LOA
60" Beam... 48" flat, with a gradual non-trip chine taper from 0" at bow to 1.5" at stern... thing turns and performs awesome! I think it ended up 25-30lbs heavier than I had hoped.. but it safe and stable feeling.
Stringers- 3/4" #2 grade Southern Yellow Pine... 7" at the transom, tapering up to 11" at the bow
Skin - regular old 7/32" pine plywood (smooth on one side) attached to stringers with liquid nails construction adhesive and 1 1/4" stainless self drilling wood screws.. counter sunk of course
Fiberglass - I used a 4" wide, 8oz fiberglass cloth tape along the transom and sides first... covering approx 2" on the gunwales/transom, and 2" on the bottom... once that got tacky, I then went back with a fairly heavy biaxial fiberglass that I laid perpendicular to the stringers... giving the strength in the opposing direction of the weaker plywood direction. The bottom then has another two resin coats applied with a foam roller to get it level and fairly smooth. Everything else on the hull just has a couple of coats of the resin.. which was West System Epoxy that I had left over from a previous project.
Paint- Light sanding on the epoxy resin, and the a single coat of two part Interlux epoxy primer.. don't recall the name.. sorry. Finish paint is a cheap ($11/qt) Rustoleum brand marine topside paint I saw at the local Lowes here. I painted the inside of the hull with that "as see on tv" rattle can water proofing stuff... and it actually works!

Metal Work
Engine Stand - I made a pretty crude stand from 3/4" EMT Conduit and some scrap 3/16" angle I had. The bottom is 1/4" flat bar. I struggled with how to connect engine stand feet to stringers.. and ultimately bolted 1/4" aluminum angle to the stringers.. with the top of the angle being flush with the top of the stringers.. engine stand was then thru-bolted to the angle with 3/8" bolts after 1/4" top deck was installed. Its probably over done, but isn't going anywhere!
Cage-1/2" EMT... with 2"x4" welded wire.. this was my first time welding tubing and the saddle cutting kicked my butt at first, but got easier. I cut with an angle grinder/cutting wheel, and then cleaned up with a bench grinder.
Rudders-I struggled with this.. but ultimately ended up making ribs out of 3/4" cedar, and skinned with some scrap aluminum roofing material from one of our jobsites... self tapping stainless steel sheet metal screws held it all in place. I was shocked at how light and stiff they ended up... they won't win any prizes at the boat show, but they work!
Steering - plain old mechanical linkage made with the 1/2" emt... I used nylon bushings and stainless lag screws to secure the rudders to the tabs I made from galvanized steel washers (also scrap from a jobsite.)
Paint- abrased slightly with s scotch brite pad.. and then 4 cans of rattle can bed liner applied... this covers up my crappy looking welds nicely!

Trailer
Bought a $599 aluminum frame jonboat trailer from local Academy outdoor store.. I had some 1/4" aluminum angle I used to widen up the main frame, and ended up cutting the axle in half, and lengething with a piece of galvanized 3x6" steel angle.. it works

Performance
OK... now the good part. The original intent was for this boat to be for my two little boys.. (5 and 6)... we own a marina adjacent to a large expanse of very shallow grass/mud/sand flats and mangroves... really couldn't ask for a better mini airboat race track. There is about 50yds of deep water to cross, and then its 12" and less of water as far as the eye can see. That being said... deep water performance was not important for this build. With 3 little boys... this thing runs awesome... and will run deep water all day long... With just me on it at 190lbs it will not get up on plane in deep water, but will hold on plane in deep water once you get up in the shallow stuff. It will do the same even with me and my 50lb kiddo on board. With me and one kiddo, it runs great in the skinny water.... will get up to around 20mph in really skinny water with just me.. probably a little less with a kid on board. I am 100% pleased with the performance in shallow water. It has now become my toy more than the kids.. making a perfect one man shuttle off to my favorite redfish hole... The problem is that it won't make the cut with me, and both my kids on board.. so a slightly larger 4a084 boat now in the works... stay tuned!

[Salty Techsan]

a few build pics... and a link to a couple Youtube videos as well

https://www.youtube.com/watch?v=czV-a-Ct22U

https://www.youtube.com/watch?v=GXDJPJukdtM

Salty Techsan

[Salty Techsan]

couple more

[hwew]

That is a very nice mini. I think I need to start thinking about building one like yours. What was the aprox cost of of materials to build the hull?

[Papee]

Great build and writeup, Was the motor new? I was just wondering because I ran a 032 for a while with a 48" ultra prop on it. I can't remember the blocks any more but I think they were 10 or 11.

[Salty Techsan]

Thanks for the kind words, and thank you Papee for being one if the first to promote the mini scene and encourage people to document their projects so we can all learn together!

Motor was indeed brand spankin' new. After reading your 032 detail, I was also surprised I wasnt turning more RPM? Did you put a tach on yours? Or just go by feel? I have noticed that performance on motor flattens out about 2/3rd throttle.... Maybe a carb jet limitation or something?

Cost for hull build materials as follows.. Roughly anyway

-$80 for plywood skin
-$65 for stringer material
-$40 in stainless wood screws
-$15 worth of liquid nails
-$0 in fiberglass and resin were free as I already had, but $100 would get this done if one were to buy boat yard grade polyester resin and cloth. Double that for the primo stuff I used.

[Doozit20]

Hey I was just wondering if a change to 100LL avgas would make a difference performance wise from regular auto grade gas??? When I get my starter setup on my boat done im going to experiment with a few minor changes to my setup including gas, with mufflers and without for both..
Steve

[Salty Techsan]

I run it b/c with the little 032 I need all the extra thump I can get.. and also like the fact that I don't have to worry about it going bad when it sits up for the summer.

[JLane]

Nice Work!

[Rollbar]

Very nice and great info/write up.

[stephen]

Nice write-up I've been looking for a mini to build. If I were to copy your build. How do you think a 22 horsepower Predator motor from Harbor Freight whould work? Any advice welcome

[Corky]

Keep it light it should work fine...I just got my harbor freight flyer in the mail...The Predator engine is on sale ....

[Kborders3]

Did you use LakeBuggy plans? I am debating on purchasing them... what are your thoughts?