Clear tarpaulin for warm, well-lit winter work?

Greenheart

Well-Known Member
Joined
29 Dec 2010
Messages
10,384
Visit site
This week has been dry, and the short days were bright so it looked to be a good time for paint and epoxy work.

I hadn't considered how cold it is. Several old-timers have told me to ignore the boasts made by paint sellers and manufacturers, about how low a temperature their products can be applied in; these (I'm told) are recipes for imperfect adhesion and finish. I've listened to a lot more advice too, about heaters and sheds, or just waiting till May.

Has anyone tried covering a low-height boat with a clear tarpaulin, in order to recreate the effect of a glasshouse?

49097226036_bc8b0f1c46_o.jpg


Not saying it will work, just looking at whether it might. The alternatives still involve some sort of tenting, but with long cables and plug-in heaters, or even generators. So the significant cost of a high-quality clear tarp begins to look reasonable; and it would remain useful for many years.

Granted, the best ones have fibre woven through, which won't admit sunlight. And a dark opaque tarp may attract more warmth than a partly clear screen. I began by thinking that stopping icy draughts is the main factor, until I realised a dark screen would still need lighting beneath, for work. But using the sun's free heat and light would be a winner.

If nobody knows any better, I'll buy one and give it a try. At the worst, it'll make wet-weather maintenance more fun.
 
Building a tent and using localised heat is a tried and tested means of working with epoxy in winter. You really need access to mains power though.

I built a tent over my boat last year using a 170g 'Monotex' tarp. It was cheap but pretty tough, and on sunny days could get fairly warm inside. Eventually it got damaged in the wind and developed pin prick holes. I reinforced the hem by rolling a 6mm rope into it and lacing that in- no more blow outs.
 
Hi
Not sure what height or size your boat is, but I was literally looking at large gazebo like things that are available at machine mart for a few hundred quid.
 
Gazebo sounds like a great way to cover-all...although I was imagining the structure of the boat would make a solid wind-proof base.

I built a tent over my boat last year using a 170g 'Monotex' tarp. It was cheap but pretty tough, and on sunny days could get fairly warm inside.

Thanks Rob. I was thinking of a fairly tough grade that wouldn't billow and ripple in every draught, and wouldn't chafe easily. I was also intending that it wouldn't stay up over the low season, but just be erected for as long as I'd want personal weather protection, and to allow a degree of 'glasshouse effect' to bring surfaces up to the temperature required for good paint adhesion.

I've heard that some tarpaulins contain silicone whose presence can mess up the painting process as badly as low temperatures. Hard to believe that silicone comes loose and floats about in the vicinity, but I'm hoping it's possible to source one made without any.
 
Last edited:
I had a boat cover custom made for our Finngulf using blue heavy pvc/canvas, the stuff used for curtainside lorrys. It was pitch black inside, difficult to rig and retain because of its weight, despite being in two overlapping pieces so that the mast might be left up, and usually dripping with condensation. It was also very expensive, about £500. The weight meant they needed more hoops and stringer battens to stop it sagging.
On our current boat we use cheap white tarps, the type you buy on line for about £30-50, seem to come from India via Devon. These are effectively translucent and it is bright under them, they are easy to place in position and do not seem to have the condensation problem, probably because I leave a large opening for getting aboard over the stern which is the downwind (eastern) side. I regard them as disposable but so far seem to get three years out of them. They gradually tear and the eyelets come out despite using shockcord and parrel balls or discs to spread the load, but I am well pleased with the arrangement. £50 per winter gives me a relatively warm, very bright and dry working space and no green moss to wash off in spring. If you buy these light covers make sure eyelets are at 50cm, max spacing so that if one pulls out you have a substitute, the bang in eyelets do not stay in place long.
Of course I am talking about Scotland where we do get more extremes of climate,
 
Well you could move the boat to Spain!
Having said that there are issues there ........too hot for painting or varnishing..condensation when you try to do it early evening etc.
One useful hint is to buy some of those plastic clips which attach to the edges of the tarps so you can tie lines where you want, they will also not tear out as easilly as eyelets.
 
The cover-all tent is a nice idea Ben, thanks. But aside from the cost (and the fact it's probably overkill for my purposes), one of my main intentions was accumulating the sun's heat under the cover, and I don't think these car-ports are available in clear fabric.

Well you could move the boat to Spain!

Thanks Mr C, that's almost as helpful as "wait till May". :rolleyes: Good point about clips for holding the edges securely, though.

There are many helpful hints here, thank you all.

My concern about silicone in some tarpaulins seems to be answered by Wikipedia: https://en.wikipedia.org/wiki/Silnylon ...it seems only to afflict a low grade of tarp, but well worth avoiding.

The message I'm getting is that clear Monotex probably represents the best cost/robustness...although I haven't found anything that specifies how the stuff is manufactured. Does anybody know if the Silnylon factor affects monotex?
 
Last edited:
one of my main intentions was accumulating the sun's heat under the cover,

Mine had a dark grey cover, light was poor, but slightest hint of sunshine and it was very warm.

Regarding epoxy, its humidity you have to be careful with, I used to hang a small dehum high up with a drain hose outside, made huge difference.
 
Good points.

I'm hoping to reduce (or eliminate) the need for corded electrics, including lighting, so the clear cover seems the best option. I wonder if anyone has tested whether heat build-up in a dark tent is greater or less than in a clear transparent tent?

I guess too much heat from the sun is unlikely in a British winter, and could be easily enough reduced by venting the covered area.
 
I've heard that some tarpaulins contain silicone whose presence can mess up the painting process as badly as low temperatures. Hard to believe that silicone comes loose and floats about in the vicinity, but I'm hoping it's possible to source one made without any.

Anyone in the spraying or furniture polishing trade will tell you that silicones are the devil's curse. Many shops will not allow things such as spray cans of WD40 & polishes etc anywhere inside the shop.
Even though one might strip a piece of furniture to bare wood & sand very well to remove all traces of stain(as I did with 14 tables for our sailing club 2 years ago) the silicone in the polish over the years can be in the wood. On applying a clear finish one gets "fisheye" this is very small bubbles rather like little pinpricks of air bubbles that rise up on the surface.
To solve the problem I had to apply several coats of shelac, at some expense, to prevent the silicone from bleaching out.
Car body sprayers use a very small amount of a chemical liquid (name escapes me at present) in the mix. I tried this, but it did not work for me.
So if you have some varnishing, or hull painting, to do, you may want to watch for that. It depends on the quality that you are looking for. If you are just slapping a few coats on then you would not be worried. But if you want a first class job !!!!!!!!!
 
Last edited:
Top