Tx River Rats Build

[txriverrat]

The ultra prop 5 blade is ordered
Arrow prop redrive with adapter for the ultra prop is on order.
This should get me up and running then I can try some of the other props and configurations.Engine should be ordered Monday
Ron

[Doozit20]

That prop should give you a lot of thrust. I think with the 5 blade it bumps it from 59" to 60" because of the larger hub.

[krwsr]

Hello fellow Texan! Got any photos to throw out yet?
Kenneth from Lago Vista{Austin}

[txriverrat]

KR
No pics yet . It will be a week or so before I start , waiting on an electrician to finish wiring my shop.

I am going to post some ideals and see if yall agree with my thoughts.
Just a little background, Ive built a single lake buggy ,and small airboat with a small motor for bowfishing 7 +11.6
and owned an 8 = 20 with 650 hp on it ,also designed and built a hover craft. As you can tell I like to build.

This boat hopefully will be the one I keep and try to clean up all my mistakes I made on the other craft
Hull design for a mini seems to preform best at 5 ft wide with no chines and up to 6 ft wide with chines.
Length doesnt seem to mater much except the added weight of a longer boat. Mine will be a 5 foot bottom and six foot top no chines and just over 10 ft long.
The 40 hp generac engine is a couple thousand bucks but it is low weight and with a carb change and a little polishing you can hit 50 plus hp pretty easy and it comes with a 3 year warranty,mine will be straight stock for awhile.
Going to run a arrow prop reduction 1.69 and a 60 inch five bladed prop. Did a lot of research and talked to a lot of folks that build air boats and it seem the general thinking is you over double your thrust when you go to a redrive. If you direct drive you do several things that limit your performance, one you have to limit your length of prop and degree it is set at, my 40 hp motor if I have to limit it to 2750 rpm probably isnt supplying 20 hp to the prop,with a redrive I can turn 3600 realizing all the 40 hp that the engine puts out,and this also allows a bigger prop because it is turning slower,1900 rpms which is more efficient
The reason for the five blade is to use as much torque as I can for heavy loads and getting on plane ,not to worried about top speed.
Last but no least I WILL HAVE SOME FLOATATION IN MY BOAT.
Ok any suggestions or disagreements are welcome
Ron

[krwsr]

Hey Ron, I love to build things as well. 44 yrs. in manufacturing as a machinist, sheet metal mechanic, and certified welder. This will be my first airboat. Built wood John boats, and 1 displacement plywood core & fiber glass. I too will be adding flotation to my rig, and a kill switch. I am going with all aluminum, not sure about a chine yet. I think I am going direct drive to start to keep cost down. I got word my 4A084 NOS shipped today. Freight cost high!!! We need to keep up with each other on our builds and get together for a run when completed. I have attempted to post a thread, but I guess I don't know what I am doing yet. Got any pointers?
Kenneth

[txriverrat]

Go to builds and at the top is a new thread button.
Ron

[krwsr]

It worked this time?? How do I add the info box at the bottom for what I am using?

[Doozit20]

Now your cooking with gas lol. Cant wait to see some pics.

My dads boat is 7' wide and is very stable in deep water and mine is right at 5'9". Mine is a little "tipyer" in deeper water but seems like it handles better in tight spots. The over all performance wise that I found is that the wider boat gets on plane quicker but has a little less on the top end then my boat though with my dads boat I find that when full out in shallow water it is much freer in the sence of it slides left and right with the slightest cross breeze. Ive only run my dads boat a few times but it performs very well.

As far as the reduction drives go as far as I know they are as you said a multiplier of the torque. Im guessing it is multiplied by the ratio you have in the reduction drive. 2:1 is twice and 1.69 is that times the torque... I know a while back chuck was doing some experimenting with a 084 and with a I think 1.89:1 was spinning a 60x38 florida airboat prop 7" wide blade wood prop. Thats a lot of prop so the reduction dribes have to help somehow lol

As far as boat widths goes I think it all depends on what your running in. With me in the glades I mainly see wet sawgrass and swampy areas that are very shallow so I think a wider boat is better to keep it sort of skipping along. If I were to be in deep water I would go for a little narrower say 5'-6' as you are suggesting with moderately high sides 16"-18" should be plenty so as to not get swamped if you have to stop quickly.

Length id say no less then 10' so you have enough room to get around and if your going for a fishing boat id say a little longer to have even more space.

Of course this is all my opinions as you said you've had several boats of varying HP and im sure you'll find a happy medium

Oh and the thing at the bottom that says the specs of your rig is called your signature in you "profile" honestly I dont remember how I did it on mine it was so long ago but I dont think it was that difficult.

Keep us posted

Steve

[krwsr]

I don't want to get to wide and to long. I like to fish and bow fish, so I need a little space up front to maneuver. I am still trying to decide on bottom and side thickness, need to make it light as I can. All of my rigging I think will be welded al., and adding flotation. Also I need to decide on starter/gen. Your thoughts?
Kenneth

[krwsr]

What welder and spool gun did you decide on? Has anyone used the Longevity MigWeld 140 with spool gun?
Kenneth

[txriverrat]

Here is the one I bought , had a lot of good reviews
http://www.eastwood.com/mig-welders-...spool-gun.html

Doozit
What are the widths of you and your dads boats top and bottom?
Ron

[Doozit20]

I actually looked into those welder a lot. They seem like a realy good buy.

Ron,
My boat has a 65" bottom and 69" at the gunnel in the back. My dads boat is 79" on the bottom and 7' or 84" on the top in the back. His bottom has a flat section in the middle about 5' and then a gradual slope to both sides before the turn up for the sides. My boat has a slight curve all the way across the bottom. His transom is an 8" transom and I think mine is aboit 12-13" id have to measure it. Both boats are 10"6" long and I can take both and spin them on there nose and right around in shallow water.
Steve

[krwsr]

Hey, I found it today doing research. I saw a demo and it looked really good. Are you happy with yours??
Kenneth

[txriverrat]

KR
I havent used mine yet still waiting on the electrician
Ron

[krwsr]

Just anxious to hear what you think before I order one; great price. Big savings on my end.
Kenneth

[txriverrat]

well reduction came in yesterday and the prop came in today ,getting my ducks in a row
Ron

[Papee]

Only one thing I would like to comment on. Length does matter, if you build a shorter boat you don't have the area to spread out the weight. Your boat will sit lower in the water and take more to get on plane. Once on plane the length doesn't matter because it is not in contact with the water. I run on the same surface area as a small boat. The only thing you are adding with a slightly longer boat is a little weight. By my figures on the weight of my boat it would be about 17lbs per foot. That's not a lot of weight considering the benefit of spreading the weight out.


The new boat I just built, a 14ft boat floats in very little water. It does not take much at all to get it on plane. It will plane out using just a little throttle.

[txriverrat]

Pappe
I agree with you up to a point,let me explain why
First boat I built was a lakebuggy single 4 + 8 wood 10 hp motor ,at that time it would plan out with my 190 lb bod in it and stay planed in deep water . Second boat was a 42 inch by nine ft bent up out of 072 (14 gauge ) aluminium,same 10 hp little boat would jump up and run with one person but was to narrow and not stable enough for me. So I added 3 more foot on the nose, helped the stability but it wouldnt plane then,so I built another prop and had another 10 hp motor ,ran twin motors ,20 hp total and she was up running good again.
Then I decided I would widen it so out came the plasma cutter and she got stretched to 6 ft bottom ,7 ft top 12 ft long .. The twins would not plane it out.
Now all that was a learning experience for me ,I was using minimum power so any change showed quickly I made the second boat narrower,less floatation ,it ran good, increased the length ,it wouldn't plane with the same horse power even though she floated shallower. had to double it, then widen it and even double the hp wouldn't plane it ,with a lot more floatation.
I looked at the high performance minis, Chucks 105 , the Dragonfly both are 10 ft boats and preform grfeat.
Ron

[froghunter]

howdy fellas. just wanted to say hi. i joined the forum today and hope to learn alot. im also in Texas and building a mini from scratch.

Good luck with it!