airboat propulsion and drive

[StianM]

I don't have a job at the moment so I have too mutch time to waste on the web. http://www.greatplainsas.com/pg58.html

[jxing62]

hi friends,
now come hovercraft. to compare hovercraft and airboat, which one is more economic to build and to maintain?
which one is more silent to operate?
the commmon of these two is , the porpulsion is located top. this will avoid damage to prop in shallow water, i think.

[COLD-EH']

Hovercraft is more complex, run short little propellers at high RPM, often multiple engines and in my opinion noisey. Airboats are simple and I think the Florida mandate is 90 Db with the boat on plane at 100 feet.

[kach22i]

Hovercraft and airboats do cross over each others areas of operation. I don't have time to do a fair comparision but I bet someone has done one. I think both are cool.

As far as noise, hovercraft using small fans with two strokes can be noisier than I like (ear plugs required). There are also four stroke hovercraft with large slow moving propellers (Sevtec) which are quieter than most airboats.

Do you own research and decide.

As far as the VW airboat, that's a new one to me. From the picture it looks like it can plane, it must be advancements in composites or something else which makes this possible.

Click on "next" in that link:

Kohler Command 25 HP engine

now that's a real over achiever.

[COLD-EH']

There are guys building 35 HP Briggs and Stratton airboats and they can run dry,( on land). But won't haul 6 people. You can make a boat quiet, efficient and capable with the right prop, and gearbox ratio. Sensenitch Superwide and 2.68/1 seems likt the quiet setup at this time. A guy with a very similar setup as mine said he hauled 10 men with hunting gear and 2 dogs up a dike and back down to water. But check this guys little boats out. his bigger stuff too!
http://www.websitedatabasesolutions....on_twister.php

[jxing62]

those links are really helpful to me, thanks.
i came across the canadian airboat and they have a builder plan which look good, have anybody has experince with their airboat builder plan? hope can share with me.

[COLD-EH']

If it's "Canadian Airboats" set of plans, I bought a set however returned them to him after realizing the product would be beyond my capabilities and budget. Fair guy to deal with for sure. Probably best getting his CNC cutting and break cd.

[jxing62]

then where can i find a more economic set of airboat plan so that i can do some modification from these plan in order to build the airboat from local available parts, i think by this mean i able to reduce the initial cost of building an airboat.
cold-eh,
if building from the canadian airboat plan, say a 16 footer, how much will it cost me?

[COLD-EH']

I would contact him and see if it fit's your means. Just best way to build his boat is probably waterjet cut. Actually I would buy the CD and have someone at least take care of the cuts and bends. I'm fine with steel and I don't have aluminum equipment and don't want to make the investment right now. If you look at the Southern USA guys hulls they are pretty simple. More stringers the stronger but heavier. I'm cheap andl like I said I'm going to do mine in steel and epoxy paint and graphite/epoxy mix on bottom. Should be real tough! With wide flat bottom boat they ever require less HP in shallow water. 500 CID Caddy direct drive are good for 6 people if you can see water you are fine. Can probably even stop on sand banks and keep going. So somewhere around 200 HP probably good for 6 people in water,direct drive from what I read. Gear boxes are about $2300.00 USD so depends on your skills and knowledge if it's more affordable to use US engine and box, make box work on what's around or make box etc. I have had quotes of all 12 gauge steel, 2 sheets 6 X 10 with 2 breaks, 1, 4 X 8 with one shear for about $600.00 so I figure I could weld up a 16' hull for $1200 CDN with plywood/glass deck. Should be 800 to 1000 LBS.

[jxing62]

cold-eh,
what is 500 cid caddy, it is ytpe of engine? and you mention about gearbox, what type of gbox it is?
i have my workshop and have mig and tig machine so alum hull is fine for me and i suggest you consider the alum hull, you can do it by mean of hand rivet. should you have problem with hand rivet pls let me know. long ago my workshop also utilise hand rivet when there are alum work but now we use tig and mig.

[COLD-EH']

Caddy 500 is a 500 cubic inch displacement engine out of an old luxury car. Lot's of torque and fairly light. Gear box I'm using is a "Rotator" from www.classicairboats.com

I have a Mig and using steel because of glacial rocks in the river and cost of material, should be a tough hull.