Custom boat lift

jcupo6

Chief Petty Officer
Joined
Jul 13, 2009
Messages
512
Okay guys I need some help/opinions. I am planing on renting a slip next season but don't want to leave my aluminum boat in the water full time. I priced some lifts/pads which range in price from $2,500-$15,000. Since I only paid $600 for the boat I'd rather not pay thousands on top of the slip fee. This can't be THAT hard to build right(famous last words)? I have permission from the marina as long as nothing is permanently attached to their dock. Below is my idea, sorry for the crappy drawing all I have to work with is MS paint.

I can get the marine board fairly cheap, this would give me a surface to walk on to clean the boat. I figured if I use bunk rollers I should be able to just walk the boat off the pad when launching. The smaller PVC pipes attached to the front would act like a ramp to reduce strain on the wench when pulling the boat up onto the pad.

What do you think?

Untitled.jpg
 

ryansdata

Cadet
Joined
Apr 8, 2010
Messages
21
Re: Custom boat lift

i have thought similarly, in designing a PWC lift. from my research, PVC pipe is denser than i thought. I think 4 inch PVC pipe has a densisty of about 1.3 relative to water - it will float but not very well. I googled "PVC PWD lift" and found some scientific data. The sites recommended 10 inch PVC, but I did not find that at Lowes, only 6inch. Good luck.

my dilemma was how to attach the wood (and for you, the rollers) to the pvc...u bolts? rope?
 

Bondo

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70,584
Re: Custom boat lift

Ayuh,... I've got a 21' islander that lives are my dock about 5 or 6 months a year, with nothing but a couple of bilgepumps...

If ya Winch it on, How ya gettin' it off,..??

My vision for such a beast consists of 8, 55gal. plastic drums, 'n 4 lengths of 4" cargo straps....

With 4 drums each side, 'n the 4 straps across each pair of drums,...
When you drive into between the 2 rows of drums, the tension of pushin' the drums apart with the boat, against the straps pullin' 'em together,...

No way it could go Anywhere, especially, Down...
 

jcupo6

Chief Petty Officer
Joined
Jul 13, 2009
Messages
512
Re: Custom boat lift

Ayuh,... I've got a 21' islander that lives are my dock about 5 or 6 months a year, with nothing but a couple of bilgepumps...

If ya Winch it on, How ya gettin' it off,..??

My vision for such a beast consists of 8, 55gal. plastic drums, 'n 4 lengths of 4" cargo straps....

With 4 drums each side, 'n the 4 straps across each pair of drums,...
When you drive into between the 2 rows of drums, the tension of pushin' the drums apart with the boat, against the straps pullin' 'em together,...

No way it could go Anywhere, especially, Down...

I'm really just trying to avoid the salt water tearing the boat and drive up. I would love to keep the boat dry, but I'm not spending thousands on a lift. I also worry about her leaking, no matter what I do I can't seem to get her water tight. I do have a pump and float switch, I guess I just worry too much.

My plan (not that I have any idea what I'm doing) was to be able to push the boat off using the rollers. Keep in mind that I have yet not tried to push my boat on the trailer rollers which can't be easy.

I've read that a 55 gallon drum can provide 440lbs of buoyancy, so 8 would be plenty. This would eliminate any worrys of her sinking! What condition is the boat and drive in when you take her out at the end of the season? I'm guessing she has a fresh coat of bottom paint every year?

Thanks for your help btw!
 

jcupo6

Chief Petty Officer
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Jul 13, 2009
Messages
512
Re: Custom boat lift

Is there any dry storage in your area?

Yeah, and I'm prolly gonna get made fun of for this but...there is a shorehouse where I currently keep the boat at about 2 miles from the boat ramp for free. My reason for wanting a slip is to eliminate the ramp. It takes me about 1 minute to launch and 2 minutes to retrieve, but there is ALWAYS either a long line or one moron who has no idea what he's doing. I would say on average I have to wait 15-20 minutes but I have waited MUCH longer than that. Took the boat out on the 4th of July and had to wait 1 hour and 45 minutes just retrieve me boat. It's horrible. I've canceled trips knowing the ramp would be a nightmare, and that just pisses me off!
 

1fishbone

Chief Petty Officer
Joined
Nov 9, 2010
Messages
476
Re: Custom boat lift

Dry storage...you call they put it in.
They use a special fork lift.

When you come back they put it away.
 

jcupo6

Chief Petty Officer
Joined
Jul 13, 2009
Messages
512
Re: Custom boat lift

Dry storage...you call they put it in.
They use a special fork lift.

When you come back they put it away.

Ah, no, not like that. The only dry storage that marinas around me offer is a parking spot and free use of their boat ramp.
 

Bondo

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70,584
Re: Custom boat lift

What condition is the boat and drive in when you take her out at the end of the season? I'm guessing she has a fresh coat of bottom paint every year?

Ayuh,... I'm on Lake Ontario,... Sweetwater....

My bottom paint is Rustoleum...

Stored Hi, 'n Dry on a platform like that,...
I'm doubtin' whether you could push it off alone...

Maybe you could rig a pulley, 'n winch pull-back capabilities....
 

jcupo6

Chief Petty Officer
Joined
Jul 13, 2009
Messages
512
Re: Custom boat lift

So I am also considering this air dock product. The total cost with shipping would be around $2,500 which is still more than I want to spend, but not completely outrageous. Does anyone have any experience with these? I have found only a few reviews, which have been positive.
 

1fishbone

Chief Petty Officer
Joined
Nov 9, 2010
Messages
476
Re: Custom boat lift

For $2500 I'll come and clean your bottom (no jokes!!).:)


Why don't you want to keep in in the water?
 

1fishbone

Chief Petty Officer
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Nov 9, 2010
Messages
476
Re: Custom boat lift

For $2500 I'll come and clean your bottom (no jokes!!).:)


Why don't you want to keep in in the water?

"I also worry about her leaking, no matter what I do I can't seem to get her water tight"

UH..before I spent $2500 on a boat lift for a leaking boat:
1. Fix the boat right
2. Take the $2500 and buy another boat that floats
 

jcupo6

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Jul 13, 2009
Messages
512
Re: Custom boat lift

For $2500 I'll come and clean your bottom (no jokes!!).:)


Why don't you want to keep in in the water?

Because I am a wuss! I am worried about her sinking (leaky rivets) and have heard\read bad things about leaving aluminum boat in salt water. I don't know, I guess you're right for $2,500 I could do a lot of preventive maintenance. I guess keeping her water tight would be the hardest part.
 

RotaryRacer

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Jul 18, 2004
Messages
1,361
Re: Custom boat lift

I once made a "lift" out of PVC pipe for a Sea Doo.

I am an engineer and I actually designed the thing with material properities in mind. I did a lot of calculations (even some simple FEAs) to prove that it would work.

It was a complete failure. PVC sucks for structural use. Any exposure to the sun and the material essentially disentigrates. I was able to lift the Sea Doo out of the water a couple of times. Then the PVC welds started to come apart and then the fittings and stuff just started cracking and breaking.

After that failure, I looked at floating the Sea Doo and found that to get enough bouyancy with PVC pipes I would need at least 2-4ft long pieces of 10" pipe to lift the rear half with the front on a pivot on shore. That was for a 800 lbs Sea Doo.

PVC pipe should not be used for anything structural and really shouldn't be used for floatation either. It makes great sewer pipe though.
 

jcupo6

Chief Petty Officer
Joined
Jul 13, 2009
Messages
512
Re: Custom boat lift

I once made a "lift" out of PVC pipe for a Sea Doo.

I am an engineer and I actually designed the thing with material properities in mind. I did a lot of calculations (even some simple FEAs) to prove that it would work.

It was a complete failure. PVC sucks for structural use. Any exposure to the sun and the material essentially disentigrates. I was able to lift the Sea Doo out of the water a couple of times. Then the PVC welds started to come apart and then the fittings and stuff just started cracking and breaking.

After that failure, I looked at floating the Sea Doo and found that to get enough bouyancy with PVC pipes I would need at least 2-4ft long pieces of 10" pipe to lift the rear half with the front on a pivot on shore. That was for a 800 lbs Sea Doo.

PVC pipe should not be used for anything structural and really shouldn't be used for floatation either. It makes great sewer pipe though.

Yeah, I am pretty much finding out that this is a terrible idea that won't work. I'll just have to put that money into preparing the boat to live in the water. Anyone have any suggestions? Just off the top of my head I will plan to gluvit the boat inside and out, then some bottom paint. Do I have to do anything with the outdrive?
 

ezmobee

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Mar 26, 2007
Messages
23,767
Re: Custom boat lift

That are dock looks cool, I just wonder how it would hold up. A jet dock would be ideal, I don't know about much they cost though.
 

jcupo6

Chief Petty Officer
Joined
Jul 13, 2009
Messages
512
Re: Custom boat lift

That are dock looks cool, I just wonder how it would hold up. A jet dock would be ideal, I don't know about much they cost though.

A jetdock for my $600 holiday = $11,000.


It's a great idea, I just don't understand why they cost sooo much.
 

jcupo6

Chief Petty Officer
Joined
Jul 13, 2009
Messages
512
Re: Custom boat lift

Holy crap! Yeah, me either.

EZ, it looks like your boat is in a slip in your pic, does it live there? It's aluminum, right? I'm guessing it freshwater.
 

1fishbone

Chief Petty Officer
Joined
Nov 9, 2010
Messages
476
Re: Custom boat lift

Engineering, time/materials!
It's a Boat:
Bust
Out
Another
Thousand

Bump those rivets, use an anti-fouling paint for aluminum, anodes, get a mop to keep the bottom clean, separate battery for the bilge pump
 
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