I'm DESPERATE

[NiceAft]

If you fix the sag, will you then be able to lift the top? If so, will that help to create an easier solution to the raising question?

[OverEasy]

I may be mistaken but wasn't there someone wanting to part out a Venture a while back???
It might be worth the while to search through the postings and classifieds to see.
If in good condition it might be worth considering before tearing into a fiberglass re-core project.

if you do go ahead with the record there is a great set of YouTubes by BOATWOKS TODAY that might be of help....

In the cases where I've recored things with curvatures I've found it a real good idea to make support cradles that can match the fwd/aft and side/side curvatures BEFORE cutting into anything.
Removal of the skin from one side or the other can really destabilize a panel and can make getting there repaired panel nearly impossible to get back into shape to fit properly.
Ive even gone so far as to beg/borrow/rent a good panel to make the support cradle.
Some of the cradles ive made over the years have been fiberglass over peel ply on the original while others have been spray foam with a smooth sheet of ply sheeting over it in a simple containment box made from scrap.

Just a couple of thoughts....

[OverEasy]

Hi TopCat0399!

wondering if you could post a couple of pictures from the side on the outside and from the front and rear along one side to help us get a feel for the actual interface geometry of your pop top to your cabin deck.
Im only casually acquainted with your boat type and I don't recall all the details to how it is supposed to fit together.....

[topcat0399]

Do these help?

In operation - Pritty gurl a-bord








Lifting with tackle






Lifting with tackle is not convenient...

[topcat0399]

I may be mistaken but wasn't there someone wanting to part out a Venture a while back???
It might be worth the while to search through the postings and classifieds to see.
If in good condition it might be worth considering before tearing into a fiberglass re-core project.

if you do go ahead with the record there is a great set of YouTubes by BOATWOKS TODAY that might be of help....

In the cases where I've recored things with curvatures I've found it a real good idea to make support cradles that can match the fwd/aft and side/side curvatures BEFORE cutting into anything.
Removal of the skin from one side or the other can really destabilize a panel and can make getting there repaired panel nearly impossible to get back into shape to fit properly.
Ive even gone so far as to beg/borrow/rent a good panel to make the support cradle.
Some of the cradles ive made over the years have been fiberglass over peel ply on the original while others have been spray foam with a smooth sheet of ply sheeting over it in a simple containment box made from scrap.

Just a couple of thoughts....

Hey - I own a 1973 Venture, I know allll about fiberglass work. I know aalllllll about cores.
Much much more than I ever ever dreamed I would. Actually never dreamed about it at all just, wham.
Over the years I have developed a serious aversion to putting rotary tools to glass.....Can't imagine why.
I have plenty of glass-work in my near future. I got caught on a lee shore, things cracked.

I get what you guys are saying though.
A stiffer board is easier to handle than a floppy one.

Its more about the mechanism to do the work, something fairly convenient and immediate.

After considering some of the replies in this thread I'm starting to think pneumatic more and more.
I the past I have not.

Can a set of air cylinders with a foot pump do this job?

[OverEasy]

Hi TopCat0399!

Wow! The photos help a lot in understanding the challenge of what you are faced with!
The pop top has very little free space outside of the cockpit opening.
The wide flange basically conforms to the cabin roof deck.
That IS a challenge!

Correct me if I’m mistaken but it really does appear that the only space you have for any mechanism or assist is either inside the cabin opening or outside the pop top.

The existing swing arms must nest pretty tightly when closed too!

Any idea of how much the pop top might weigh?

Best Regards
Over Easy

[Jimmyt]

The poptop is approx 60" square (if there be such a thing on a Venture)
And might weigh approx just North of 100 lbs.

[OverEasy]

Thanks JimmyT!
I missed that.
Got my glasses on now

[OverEasy]

Hi TopCat0399!

If/when you do your re-core of the pop top it might be a golden opportunity to make bump out spaces to fit something like those neat air-lifters or something else that yo feel would work.

Kind of serendipity with needing/wanting to do that project.

Not knowing what you have onboard for power (such as 12VDC batteries) the air lifters could be inflated by a had pump but it might take quite a few pumps. I’ve had an portable air pump previously that had an integral 12VDC rechargeable battery which was capable of fully inflating a 60 psi truck tire but it was a bit heavy.

A more up-to-date and lighter nicer option would be something Ryobi currently makes that uses their One+ 18 volt lithium battery system. I believe one could get several inflation cycles of the pop top air lifters from a 4 or 6 Amp hr battery.


There are several other options available with a variety of additional functions above just an air compressor such as Jump-Start, built-in 115VAC inverters, USB ports, area lamps, spot lights, etc… such as offered by Harbor Freight



So it looks like there might be a couple options from which you might want to choose to pursue that could work out with the pop top re-core project!

As my Dad used to say “What a great opportunity to make Lemonade!”

Best Regards
Over Easy

[Jimmyt]

Thanks JimmyT!
I missed that.
Got my glasses on now

Anytime OE. Glad to help keep the creativity flowing.

And, they still make those exhaust powered lift bags...

[Jimmyt]

After considering some of the replies in this thread I'm starting to think pneumatic more and more.
I the past I have not.

Can a set of air cylinders with a foot pump do this job?

The short answer is yes. How strong is your leg, and how long are you willing to pump to raise it? It is much more difficult, though, to figure out how to lift it without destroying it, or having the lifting hardware destroy the livability of the boat.

My personal preference would be a lower pressure, more distributed lift system. I'm concerned about the condition and structure of the top being able to withstand the lift if you use a conventional cylinder to work with the linkage you have. After you zero in on an idea and make a sketch, maybe post it for comment. As always, though, your boat, your rules.

From my brief look at this, it would be easier to buy pneumatic cylinders and bolt them in than designing lifting bags and making them (or having them made). So, I'll respect you either way you go! I'm more prone to make things overly complicated, involving as much R&D and custom fab as possible... Most of my friends encourage me not to help them with their projects.

You can get a long enough stroke pneumatic cylinder to make it happen. This one goes 18", and they can go longer. I would still encourage you to design a mechanical position lock to hold it in place after you get it where you want it.

https://www.automationdirect.com/adc/sh ... pUEALw_wcB

[Wyb2]

I think I read all the replies, might have missed a similar suggestion, but here’s my vote:

Install the normal gas struts the same way people have documented in the past. Then, replace the stanchions/poles that currently prop the top in the up position with telescoping units of some kind (custom of 2 pipes of slightly different sizes, or maybe there’s something pre-made out there). Then drill say 10 holes in each pole at the same locations, and get 2 trailer coupler pins that fit in those holes. Now you set the poles to whatever length you want, and raise and set the top by hand with the help of the gas struts.

[OverEasy]

Hi JimmyT!

Yeah! I remember those bags!
we tried using them back when I was a City Medic back in days of yore!
They work great for vehicle stabilization and levered lifting as one point of three where the other two points were hard contact point to pivot against.
They were a bit loosey-goosey when attempting to lift a whole vehicle with three bags though..
Huge lift capability in a very flat package.
They had their uses!!!

Best Regards
Over Easy

[topcat0399]

I think I read all the replies, might have missed a similar suggestion, but here’s my vote:

Install the normal gas struts the same way people have documented in the past. Then, replace the stanchions/poles that currently prop the top in the up position with telescoping units of some kind (custom of 2 pipes of slightly different sizes, or maybe there’s something pre-made out there). Then drill say 10 holes in each pole at the same locations, and get 2 trailer coupler pins that fit in those holes. Now you set the poles to whatever length you want, and raise and set the top by hand with the help of the gas struts.

I don't know much about gas struts I guess, how do they act when stopped mid travel?
They want to continue pushing until end of travel right? In either direction.
So if you stop it anywhere mid travel it has stored energy right?

So once a strut starts upward I would have to "capture" it when the top is say.... 12" up.
And then when I'm done with the top to close it again;
I would have to "release" it and the top would continue all the way up.
And then I could push on it to reverse direction and close it.

Do I have that right?

Will a gas strut reverse direction midtravel?

Struts is very mysterious.

[Jimmyt]

If you pick them correctly, and match up the forces during the stroke, it should result in essentially balancing the weight of the pop top. It acts like a spring and damper; exerting more force the further you compress it. If you were able to perfectly match the attachment angles, load, stroke, etc. to the strut capacity, the pop top would stop at any point during the stroke and be perfectly counter-balanced such that slight pressure would move it up or down.

It would be a pretty decent mental exercise to do the numbers, then you'd find that the struts weren't perfect. Most vehicle hatches, trunks, etc tend to stay down during the early part of the stroke and move upward during the latter part. Some will come completely open when you release the latch. So, your thought that it may either fall down a bit, or continue to move open, when stopped mid-stroke, is likely valid. They also seem to change characteristics over time on my vehicles. But, I keep vehicles a very long time.

Hydraulic would likely give the best position control. Pneumatic might be a bit springy, and the struts would just make it easier to operate manually. All three will probably need mechanical stops to safely hold the top in position.