Clear Shrink Wrapping questions

[limbodog]

Hello,

I've got a shrink wrapping company coming to wrap my boat... someday. They don't give ETAs really, they just do 'em in the order they are received. (these guys are the recommended ones in my area)

They charge a flat rate based on boat LOA, and then charge for materials. They use wood to make the frame, I've noticed.

So wood is fine, but it seems like it's less ideal for taking apart and storing later based on the construction I've seen them do on the boats around me. Looks like people who go wood just start fresh each year.

Well, I have a storage space on land for all the stuff I don't want to keep on my boat, and I was thinking it might be good to make my own frame, and then just have the company do the actual wrap. That way I can disassemble the frame for next year.

This may be a terrible idea tho'. Please hit me with a mackerel or something if it is.

But I was thinking about building a 1" PVC frame along my 40' sloop.

For the spine joints (where the ribs connect) I would use these: https://www.globalindustrial.com/p/s...rade-pvc-green

And then I'd either let the PCV bend to connect to the deck, or I'd put in joints along the ribs to help them bend: https://www.globalindustrial.com/p/s...rade-pvc-white

My deck has aluminum gunwales with openings in it every 8" or so, so I could easily secure the feet of the ribs to that.

Each joint could be screwed into place, rather than glued so that they have a strong bond, but also be easy to disassemble / reassemble for next year.

My questions are:

1. Is this stupid, should I just let the pros do it and be happy that I can afford to pay them.

2. Is 1" PVC a bad idea because it's not strong enough to hold whatever snow comes my way and it'll buckle?

3. Is it actually a lot harder than it looks? (Honestly, it looks like my years of playing legos and erector sets as a kid have finally come in handy)

4. Will PVC not hold up to multiple years of use and I'll end up having to replace it all anyway?

Thank you in advance

[SV Siren]

I made a 2 1/4" frame for mine, and spent a ton of hours (35-40) custom cutting and fitting, and spent about $850 on tubing from home depot. Now I will say that I had 40" high sidewalls, as I wanted to be able to work all year around if I wished to. We are in a high snow area as well. That said it failed, I watched it collapse after one really big wet heavy snowfall. Once that happened there was nothing I could do, and it was a huge mess.

[IMG] [/IMG]

PVC gets very brittle in the cold, and will shatter under a heavy load.

I went to metal conduit this time, and it has been fine. Once again home depot parts, spent $450, and borrowed a bender. The conduit fabrication took one 6 hour day.

[boatman61]

Ban single use plastics..

[Bill O]

A 2x2 wood frame is better than 1" pvc and when labeled correctly can be reused for many years.
As described by Siren, the pvc isn't stiff enough/becomes brittle and can't handle heavy snow loads. Using metal conduit is a good idea. Also a steep roof slope is important to help the snow slide off. Even with all that, expect to make a run to the boat to help pop off the snow during a NE'er before it builds up too much. If you are living in it, even better.

We used a 7 mil. reinforced clear plastic (Dura Skrim) for our dome a few years ago and worked well for our needs. It is much cheaper than shrink wrap and technically it could be used several years if one was careful when removing it. They make more generic versions of this product now but we went w/the name brand and it worked well.

Shrink wrap is usually a one and done, but does have the advantage of adding strength to the structure when its pulled tight. Helped some professionals shrink wrap boats to learn the tricks before I did my own. Its fairly easy with the right propane gun.
In the added pic, we'd needed to do some main cabin work and didn't pull the sticks, so we made this structure between them using the Dura Skrim. We added extra doors to get fore/aft and this also allowed extra ventilation during the springtime if it got too hot in the dome.


Bill O.

[Ivanvet]

Hi,

It's our first winter in Boston too, and we opted for building it with 1 1/2 PVC tubing. I wanted to reuse the frame for the next few years, as long as it lasts. I finished the frame 2 days ago and am waiting for the shrink wrap (as you said, one of these days...).
What I would like to do is to through bolt all the joints to make sure they don't fall apart, although the shrinkwrappers team were saying that it maybe over kill, and that once the plastic is heated it will pull everything pretty tight. After seeing the comment above, I don't think anything is overkill. S/V siren, was your wrap heated? or just wrapped around it?

Anyway, send me a PM if you want to have a look at it. I cannot recommend it yet, but I'll have a pretty good idea after few noreasters!

[Pete17C]

if you go with PVC frame, maybe use schedule 80 (typically grey) instead of schedule 40 (typically white) for it's higher strength

[Hardhead]

If you want to go a slightly different route, you can find a lot of very large, practically custom sized, very good quality tarps on the internet/amazon now-a-days. I made up a nice cover set-up with a large heavy duty tarp, shock cord, stainless snap hooks, and PVC "V" shaped frames. I impress myself every time I look at it-

[LeeV]

This: 2. Is 1" PVC a bad idea because it's not strong enough to hold whatever snow comes my way and it'll buckle?

[Bill O]

Besides snow load be sure to account for the potential of strong side winds (>50kts). This is another part of building the structure so it doesn't rack out w/high winds and where wood has possibly more multi dimensional strength/stability than other framing materials.

[Ken Pole]

Indulge my ignorance here (I have an aluminum frame and fabric cover) but won't clear shrink wrap create a greenhouse with high internal moisture levels? If so, good air flowthrough would be critical.

[Cheechako]

Have them leave some openings in the wrap to allow air flow. Otherwise you have a mold generator. Clear wrap? No, unless you need the light.
You can make a pvc frame or wood. It IS a lot of work for sure and I would expect to revise and redo a couple times to get it right. I would make the "station line" frames glued together (if pvc) and the longitudinals unglued for easy assembly and disassembly and storage.
I would use PVC, at least 1".
I used 3/4 pvc for a 24 ft boat cover and it's too flexible.

[BlueChicago]

Originally Posted by limbodog

1. Is this stupid, should I just let the pros do it and be happy that I can afford to pay them.

2. Is 1" PVC a bad idea because it's not strong enough to hold whatever snow comes my way and it'll buckle?

3. Is it actually a lot harder than it looks? (Honestly, it looks like my years of playing legos and erector sets as a kid have finally come in handy)

4. Will PVC not hold up to multiple years of use and I'll end up having to replace it all anyway?

The pros that did mine last season used three vertical 2x4's that were about 6' tall along with plastic palate strapping to tie it all together into a a rigid structure. The 2x4's were distributed along the centerline of the boat. They then topped all the stantions and tops of the 2x4's with old plastic bags or rags to ease the sharp corners, and then shrink wrapped the whole structure including the topsides. It was sturdy. Much easier than building a reusable frame.


However, I would not do it again. As mentioned by Boatman, it is one-use plastic (unless they are recycling the plastic). Plus, even though I wanted to, I could not work under the tent because of the strong out-gassing of the shrink wrap plastic (perhaps that is because I opted for the clear plastic).


If you are going to go to the effort of a re-usable frame, I would recommend that you also fabricate (or have fabricated) a reusable cover. I would research the cost, as you may find that a reusable cover is less expensive than you expected - especially if you DIY.



Good luck!

[Hardhead]

This is a little off topic - but if anyone needs any good quality, but cheap, stainless snap hooks for lashing things down - I've used a ton of these for shock cord, etc.

https://www.amazon.com/Pieces-Stainl.../dp/B06Y4XF85Z

[antoha]

i have tried using 1" white pvc in the past, didn't work: looked nice when I'd first put it up, and would be a sorry sight after a dump of snow.

go with fairclough - they are pricey, but do a good job, and don't try to pull your leg. they won't give you a "lifetime warranty" (like some other shops may) because they know the cloth cover will degrade and need to be replaced. however, they will rebuild it for you (at cost of materials + labor prices, without additional markups) once the fabric wears out 10-15 years down the line.

I didn't do that, and instead went with "the other guys who give you a lifetime warranty" (it's been 8 years and I have to basically beg them to do any alterations, because their original design simply doesn't work; their turnaround to commit to anything is 3 months to a year, and then they either do it poorly or kick the can to the next yet and use every chance to blow you off; they do use good materials I have to say, so it's not all terrible - just that they can't design the tent or cut it right) and you know - penny wise...

I ended up replicating faircough frame design with conduit + lashing strips of wood. I also bought castings from them (which connect the spine of the frame to its ribs).

just my two cents.
anton

[pcmm]

I used to do this for winters when living aboard. But instead of PVC I used black ABS pipe 1.25" for the ridge with the 1.5" Tee's (they slide in place over the ridgepipe nicely. keep the vertical sections to basically stanchion height an then a 45 to create the rafter all the way to the ridgepole. Worked really well. clear shrink wrap costs extra $$ but if you're living aboard it's well worth the expense for the greenhouse effect it provides