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Waterproofing canvas

Posted: Sat Aug 22, 2009 12:06 am
by Alric of Drentha
I have a tent made from some canvas which is, I fear, a little bit too thin. I mail ordered it, and I think they sent me the wrong fabric... regardless, the fabric is now a tent, and I'm worried about camping in the rain because the last time I camped with it in the rain I got a light mist through the fabric. The fabric is a 100% cotton canvas.

My question is, what are some ways I can stop this light mist from coming through the fabric? I'm interested in period and non-period solutions.

I tried a commercial waterproofing spray on a fabric sample, but it didn't seem to do very much. Are there other options I don't know about?

Thanks!

Posted: Sat Aug 22, 2009 12:24 am
by Christophe de Frisselle
Parafin

Posted: Sat Aug 22, 2009 12:38 am
by B. Amos
I used Starbright waterproofing to re-waterproof a tent, it worked well.

Posted: Sat Aug 22, 2009 12:59 am
by Alric of Drentha
Christophe de Frisselle wrote:Parafin


What would be the best way to apply it? Rub it on and melt it into the fabric? Dissolve it in turpentine and paint it on?

Posted: Sat Aug 22, 2009 1:20 am
by Sasha_Khan
Alric of Drentha wrote:
Christophe de Frisselle wrote:Parafin


What would be the best way to apply it? Rub it on and melt it into the fabric? Dissolve it in turpentine and paint it on?


Are you intending to live inside this candle?

Posted: Sat Aug 22, 2009 6:36 am
by Christophe de Frisselle
</derail>
I just bought a cavas tarp for a dayshade. In my searching, I found a place selling waterproof tarps that used parafin for the waterproofing. Likely not very good for my purpose or yours. Definitely not fire retardant.
</derail>

A quick google of "waterproofing canvas" show a good half dozen or more products and instruction for application. Apparently, silicone is bad.

Posted: Sat Aug 22, 2009 7:54 am
by chef de chambre
Sasha_Khan wrote:
Alric of Drentha wrote:
Christophe de Frisselle wrote:Parafin


What would be the best way to apply it? Rub it on and melt it into the fabric? Dissolve it in turpentine and paint it on?


Are you intending to live inside this candle?


I am pretty sure a historically waterproofed tent, with beeswax, is in no way a candle. The tent fabric does not have the properties of a wick made to burn without going out, for instance. People who are used to modern candles have never dealt with the gyrations required to keep historical ones lit.

Waxing canvas (beeswax, not parafin) was probably the primary method of waterproofing tents, up to the 19th century. I haven't seen a lot of cases of accidental tent arson, in the normal act of camping, historically. It seems to have taken intentional acts of arson to get them going.

If the wax fully penetrates the fabric, both sides, then it seems to me that fabric won't logically be able to work like a wick. Keep in mind, while modern candles burn without assistance, pre-late 19th century candles required attention to keep them going, wicks required trimming, or the candle would go out by itself when the flame hit wax.

Posted: Sat Aug 22, 2009 7:55 am
by Baron Conal
I've heard Thompson Water seal works....
Never tried it personally.

Do not get the thicker formula.

Posted: Sat Aug 22, 2009 8:34 am
by ^
Baron Conal wrote:I've heard Thompson Water seal works....
Never tried it personally.


I have works fine.

Posted: Sat Aug 22, 2009 8:47 am
by Guy Dawkins
Piers Brent wrote:
Baron Conal wrote:I've heard Thompson Water seal works....
Never tried it personally.


I have works fine.


It does contain petroleum. Not a candle...more a torch.

Anyone ever tried Canvak?
http://outfitterssupply.blogspot.com/20 ... -tent.html

Posted: Sat Aug 22, 2009 9:05 am
by knitebee
before using any water resistant treatment set it up and hose it down with water. Water will cause the fibers to swell closing up much of the pores in the canvas.

I've personally used Aqua-Tite® http://www.seattlefabrics.com/waterproofing.html on my pavilion. I have a poly/cotton blend canvas and water sheets off it like its aluminum siding, I can't vouch for how it works on straight coton canvas though. Mine did get a light misting through it once but there was 40+mph winds and over 4in of rain that day.

more info for you http://midtown.net/dragonwing/waterproofing.htm

Posted: Sat Aug 22, 2009 9:11 am
by Maeryk
canvas is waterproof all by itself. Set the thing up somewhere and let it rain on it, and see if it's an issue BEFORE you go painting crap on it.

Initially, you'll get minor leakage, until the fibers swell. Even with the most waterproofed canvas ever, you'll get a light mist through the fabric in heavy rains.

But I'd reccomend at least finding out if it's going to be an issue before you go spraying chemicals on the tent.

Posted: Sat Aug 22, 2009 9:59 am
by Baron Conal
Guy Dawkins wrote:
Piers Brent wrote:
Baron Conal wrote:I've heard Thompson Water seal works....
Never tried it personally.


I have works fine.


It does contain petroleum. Not a candle...more a torch.

Anyone ever tried Canvak?
http://outfitterssupply.blogspot.com/20 ... -tent.html


What is the solvent in Canvak?

( a little googling later.... It's the same as Thompson's )

The solvent in Thompson's is naphtha and once that evaporates
is it still any more flammable than the canvas was to start?

Posted: Sat Aug 22, 2009 12:10 pm
by ^
Baron Conal wrote:The solvent in Thompson's is naphtha and once that evaporates
is it still any more flammable than the canvas was to start?


I never had my tent catch fire but never really feared it either.
It is a pretty simple experiment. Take two lengths of canvas equal length coat one in thompsons then let it dry very thoroughly, I'd say a week outside if possible. Then hang them both and get a stop watch. light the non treated one and see how far and how fast it burns then do the same to the other. I suspect thompsons would burn more quickly and thoroughly but not to a dangerous level. It also should be noted that Sunforger is not flame resistant unless treated so.

I personally question whether medieval tents were waterproofed. A good canvas especially hemp should seal pretty tight when wet and should shed water well with a decent steeper then 45% angle. One of the pannels of my tend I made did not get treated before the first time I used it in the rain which was at Retreat from Calais, while I don't think we got a hard rain, then panel shed most of the water with occasional drips or sprits from good drops or what not and it was just cheap painters canvas.

So while this is more an Historical Research question what is the earliest reference we have to large scale waterproofing of tents.

Posted: Sat Aug 22, 2009 12:25 pm
by chef de chambre
Piers Brent wrote:
Baron Conal wrote:The solvent in Thompson's is naphtha and once that evaporates
is it still any more flammable than the canvas was to start?


I never had my tent catch fire but never really feared it either.
It is a pretty simple experiment. Take two lengths of canvas equal length coat one in thompsons then let it dry very thoroughly, I'd say a week outside if possible. Then hang them both and get a stop watch. light the non treated one and see how far and how fast it burns then do the same to the other. I suspect thompsons would burn more quickly and thoroughly but not to a dangerous level. It also should be noted that Sunforger is not flame resistant unless treated so.

I personally question whether medieval tents were waterproofed. A good canvas especially hemp should seal pretty tight when wet and should shed water well with a decent steeper then 45% angle. One of the pannels of my tend I made did not get treated before the first time I used it in the rain which was at Retreat from Calais, while I don't think we got a hard rain, then panel shed most of the water with occasional drips or sprits from good drops or what not and it was just cheap painters canvas.

So while this is more an Historical Research question what is the earliest reference we have to large scale waterproofing of tents.


The tents purchased by the comptroller of the artillery of the Duke of Burgundy were coated with beeswax. This is circa 1470's.

Posted: Sat Aug 22, 2009 2:34 pm
by ^
chef de chambre wrote:The tents purchased by the comptroller of the artillery of the Duke of Burgundy were coated with beeswax. This is circa 1470's.


Can you quote it from the source or give the reference so we can find it and see if we can get an idea of a ratio of how much bees wax was used per tent?

Posted: Sat Aug 22, 2009 2:42 pm
by chef de chambre
Piers Brent wrote:
chef de chambre wrote:The tents purchased by the comptroller of the artillery of the Duke of Burgundy were coated with beeswax. This is circa 1470's.


Can you quote it from the source or give the reference so we can find it and see if we can get an idea of a ratio of how much bees wax was used per tent?


The source is Gardinier, and it gives absolutely no clue as to ratio, it just says tents beeswaxed for waterproofing. I'll go try to hunt it down. I should write down page numbers as I come across these things, but I have primarily been looking to details regarding artillery accoutrements, rather than tents.

Posted: Sat Aug 22, 2009 3:02 pm
by Maeryk
chef de chambre wrote:
Piers Brent wrote:
chef de chambre wrote:The tents purchased by the comptroller of the artillery of the Duke of Burgundy were coated with beeswax. This is circa 1470's.


Can you quote it from the source or give the reference so we can find it and see if we can get an idea of a ratio of how much bees wax was used per tent?


The source is Gardinier, and it gives absolutely no clue as to ratio, it just says tents beeswaxed for waterproofing. I'll go try to hunt it down. I should write down page numbers as I come across these things, but I have primarily been looking to details regarding artillery accoutrements, rather than tents.


The whole tent? Or just the seams?

Posted: Sat Aug 22, 2009 4:36 pm
by ^
chef de chambre wrote:The source is Gardinier, and it gives absolutely no clue as to ratio, it just says tents beeswaxed for waterproofing. I'll go try to hunt it down. I should write down page numbers as I come across these things, but I have primarily been looking to details regarding artillery accoutrements, rather than tents.


Yea you need to create some sort of indexing system or something for your references. Especially for books that don't have good indexes.
I wouldn't be surprised if we had to go to the original document to get some sort of quantity.

Posted: Sat Aug 22, 2009 10:04 pm
by Kilkenny
I knew some folks with a tent made of untreated muslin. It was named "Don't Touch, the Tent". This was because, as long as you did not touch the fabric, rain sheeted down to the ground and did not come off the walls or roof. Zero waterproofing of any kind. Minimal misting through in heavy rain.

Touch a spot on the roof and get in a world of trouble though, because that spot would act like the sink drain and water would pour through :shock:

Beeswax and paraffin are both flammable. Many things were done historically that we have since learned to consider unacceptably risky. I think waterproofing tent fabric with wax probably falls in this category.

Posted: Sun Aug 23, 2009 7:05 am
by Johann Lederer
I used Thompson's water seal on my Civil war A tent...never again. It shed water well but the smell was unbearable for close to a whole season.

Posted: Sun Aug 23, 2009 7:42 am
by Adric13
I used the canvak on the tent I made. That was 6 years ago. I am planning to retreat it soon. I didn't mind the smell cause there was one but Not too over powering. It seemed to help cut down on the misting when the rain first started.

Posted: Sun Aug 23, 2009 10:32 am
by Malachiuri
Paraffin works great for waterproofing canvas.

Just ask all those nice folks who attended the Hartford Circus in 1944. Paraffin typically has to be combined with a solvent, most often a nasty petroleum base. The paraffin does stay crazy flammable even after the solvent evaps off. Bees wax seems not to do this.

I know this for a fact.

Master Gottfried and I did an experiment in 2006 after seeing the history channel show about the circus fire. We tried both and the paraffin soaked canvas was damn near tinder material. Beeswax was much, much harder to get lit. Its cared us, we were very very close to waterproofing our wedge tents with paraffin before we saw the show...

Thompsons works ok, I prefer the el cheapo WallMart knock off. Its clear instead of yellow, has less smell and seems to be less oily.

Canvak is the shit. I have used it for pavilions, boat covers and awnings for years. Its specifically made to do what you are looking for. Why look elsewhere? Dont use a crescent wrench as a hammer...

Posted: Sun Aug 23, 2009 12:05 pm
by sha-ul
I remember reading here about using latex paint mixed in a 1(paint):3(h2o) ratio with water to "paint" the canvas & seal it

Posted: Sun Aug 23, 2009 4:26 pm
by Christophe de Frisselle
Malachiuri wrote:Paraffin works great for waterproofing canvas.

Just ask all those nice folks who attended the Hartford Circus in 1944.


Also worked well for the Hindenburg. They used gasoline as the solvent.

Posted: Sun Aug 23, 2009 4:47 pm
by sha-ul
Christophe de Frisselle wrote:
Malachiuri wrote:Paraffin works great for waterproofing canvas.

Just ask all those nice folks who attended the Hartford Circus in 1944.


Also worked well for the Hindenburg. They used gasoline as the solvent.

I had heard instead of paraffin on the Hindenburg, they used a mixture of powdered aluminum,& Iron oxide the resulting paint closely resembled thermite

Posted: Sun Aug 23, 2009 5:42 pm
by Christophe de Frisselle
The AL & Ironoxide was painted on to provide a conductive surface for any static charge.
Though the Hindenburg was a unique confluence of circumstances that would be odd to fine with a canvas tent. Thought a candle in a paraffin coated canvas tent comes close.

If the canvas is thick enough, I would think it wouldn't need any waterproofing.

Posted: Mon Aug 24, 2009 11:29 am
by MelanieC
sha-ul wrote:I remember reading here about using latex paint mixed in a 1(paint):3(h2o) ratio with water to "paint" the canvas & seal it


That's a good ratio for painting one's tent because it thins the paint enough that it can get into the pores and not sit on top of the canvas. I used a 1:2 ratio when I painted my pavilion this summer and had no leaks along the paint lines during all the rain at Pennsic. That being said, I don't want to think about how heavy a fully painted pavilion would be!

My husband used Canvak on the shade fly I made earlier this year out of a fairly thin cotton canvas. We stayed mostly dry during a heavy downpour at an event, but there was a bit of misting under the shade. I attribute that more to the light weight of the canvas rather than a failing on the Canvak's part. As stated before, Canvak is fairly stinky. I figure it'll probably be a year before I don't smell it on the shade anymore.

Posted: Mon Aug 24, 2009 2:37 pm
by Jon Terris
I have made a couple of awnings so far using linen canvas which I proofed with linseed oil and lanolin- effectively making oilcloth.

They work very well in heavy rain (I did need to re-apply after the initial coat where I had missed a spot or two) even holding water in large pools (until I added more guy points and poles!)

Cover one side of the fabric in lanolin (I got mine from an equestrian supplier for blanket wax).

When that has dried (a day or so) paint the other side with linseed oil (actually, I used a sponge rather than a brush).

And yes, I know that linseeded rags can spontaneously combust but when they are dry they are quite harmless (I dried the whole awning in the garden for a few days to be safe!).

I know of folks who use Thompsons water seal to varying degrees of sucess, it seems to wear out in areas where the fabric is folded regularly.

JonT

Posted: Mon Aug 24, 2009 2:43 pm
by Maeryk
Christophe de Frisselle wrote:
Malachiuri wrote:Paraffin works great for waterproofing canvas.

Just ask all those nice folks who attended the Hartford Circus in 1944.


Also worked well for the Hindenburg. They used gasoline as the solvent.


The Hindenburg was painted with a rubberized aluminum combination that is basically Solid Rocket Booster fuel.

not paraffin.

And it was filled with hydrogen.. another issue you (probably, unless it's Ansteorran Chili Night,) won't be dealing with in a tent.

Posted: Mon Aug 24, 2009 4:40 pm
by mordreth
If you're going for traditional waterproofing I'd strongly suggest you check into fire discipline from an old army, or boy scout fieldbook.
There are reasons fire resistant canvas is popular for tents.

Posted: Tue Aug 25, 2009 8:18 am
by earnest carruthers
"canvas is waterproof all by itself. Set the thing up somewhere and let it rain on it, and see if it's an issue BEFORE you go painting crap on it. "

Yep, Mathijs, who sometimes posts here made his own linen canvas tent, as far as I know uses no waterproofing, the tension on the cloth causes it to resist water.


re beeswax, although it may have been used as a waterproofing for C d B's artillery tents, it is hugely expensive due to the way hives were managed.

I would hazard that it makes sense for someone of C d B's standing, but question a wider use for normal people.

Also, beeswax is solid at room temperature, it can be dissolved in linseed oil to make a sticky and reasonable sealant, it can also be dissolved in spirits of turpentine, used for furniture polish, but in that loose form is flammable. But I would still err on the side of caution in terms of how much beeswax you would need for a tent, in terms of cost.

Oiling cloth will add to its waterproofing, but also its weight, plus it would have to totally dry before packing, due to possible combustion.

The only waterproofing recipes I have seen are for cloth windows, either suet or oil/varnish, much cheaper than beeswax and just as good

Oil varnish is easy to make:

boil linseed oil with colophony (pine resin), say 2:1 ratio, boil until thick like honey, apply, allow to set. Again paying attention to the drying.

I have made varnish a couple of times and it is time consuming but gives you a good result, as it can be used as a paint medium for metal and wood.

Posted: Tue Aug 25, 2009 11:58 am
by ^
earnest carruthers wrote:I would hazard that it makes sense for someone of C d B's standing, but question a wider use for normal people.


While kinda off topic it kinda assumes that normal people would be making or buying tents.

Posted: Tue Aug 25, 2009 12:19 pm
by earnest carruthers
"While kinda off topic it kinda assumes that normal people would be making or buying tents."

Precisely, unless all who buy tents are high rankers, but normal in the sense of not being Charles the Bold, but I would totally agree with you ;-)

Posted: Mon Aug 31, 2009 12:35 am
by Alric of Drentha
Thank you for all of the fantastic replies!

I camped in my tent this weekend, and as I expected it was subjected to some really hard, driving rain. As I feared, the tent misted inside... the canvas I used isn't tight enough to keep it all out. When the rain reached its hardest, the inside of my tent felt like the mist sprays some supermarkets have to keep the vegetables fresh... rather like someone had a spray bottle and was squirting it toward me. My old, smaller tent was made from heavier canvas, and didn't do this.

On the one hand, this is very annoying. My blankets were damp, and I had to make sure I didn't have anything that had to stay dry sitting out. On the other, it was far better inside my tent than outside it; I will take mist over torrential downpour any day, and many people's mundane tents were leaking badly. And my damp wool blankets still kept me warm. When it rained again in the morning, the canvas had absorbed the water, swelled up, and I didn't get any more mist.

I now have to decide if I'm ok with being misted on when it rains, or if I want to experiment with a few of the ideas above.