Author Topic: Waterproofing Canvas by "paraffinning".  (Read 118 times)

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Offline buzzacott

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Waterproofing Canvas by "paraffinning".
« on: September 23, 2017, 12:32:43 AM »
Taking a cue from this excellent thread - http://bladesandbushlore.com/index.php?topic=1356.0 - I thought I'd post a method I've used quite a few times for waterproofing cotton canvas and japara (known as balloon silk/egyptian cotton to old timers like Horace Kephart). In the olden days in North America, Britain, and here in Australia, they called this method "paraffinning". It's a dry proofing treatment which doesn't increase the weight of the material or make it greasy or oily like a "wet" treatment like oilskinning.

I used a mixture of white paraffin wax and a solvent. The solvent I used is called "white spirits". It's like a low-odour mineral turpentine and I believe it's used as a dry cleaning fluid. I have also experimented with shellite (Coleman stove/lantern fuel) and I've used unleaded gasoline. White spirits works best, followed by shellite, with gasoline coming in third because it takes a few days for the gasoline smell to leave the waterproofed article.

I'd love to try the alum recipe at the link above, but I can't find it locally, whereas white candles (they're paraffin wax) and  white spirits are cheap and easy to get in just about any hardware store here and in some supermarkets too.

Here's how you do it -

Bring a big pot of water to the boil and then remove from the flame. In a smaller metal pot which fits inside the big one, place broken candles (or unbroken tealight candles) and stir around until they start to melt. Don't worry about removing the wicks. You can pick them out later without damaging the waterproofing. If the inner pot with melty wax in it starts cooling, remove it and put the water pot back on the stove until it boils, then keep stirring.

Making doubly-sure there's no flame or heating element anywhere near it, pour the solvent into the molten wax and stir thoroughly. It's now ready to use.

You may be asking what proportions of wax to solvent. When making up a batch to reproof a tarp or japara tent I use about 600 grams of candles and 1 litre of solvent. You could go a 50/50 mix without any problems I reckon. I only use 600g of candles because my household candles come in packs of six, and each candle weighs about 100 grams - hence 600 grams, or as my insect brain sees it - one packet of candles to one bottle of white spirits :-D

To water proof an article like a tarp, just pitch it taut in a lean-to fashion, then using a wide paint brush, paint the mixture on to the outside surface, being sure to put some extra on any seams or stitching. In a few hours or overnight, the item will be dry and ready to pack away or use.

How does it work? The solvent carries microcrystals of wax into the very fibres of the cotton and when the solvent evaporates off, the wax stays in the fibres, leaving the fabric feeling completely dry and maybe a little silky. I haven't done it, but you could do this with cotton clothing too if you wish.

If you haven't used all of the proofing mixture you can store it in a sealed tin or a jar. I had half a batch left over a few years ago and I put it into an old coffee tin. Fully three years later, I cracked open the tin and found the stuff to be perfect, with no separation of the two components or evaporation of the solvent.

Using flammable liquid and flammable wax sounds like a recipe for disaster for an item which may be subject to embers and sparks from the campfire. Fear not. We did a fire-susceptibility test on this stuff. I had a couple of squares of calico (I think you guys call it muslin). I treated one with the paraffin/solvent mix and left one untreated. The following afternoon, we pegged both o a wire slung taut between two trees and lit the bottom corner of each. They both burned and charred in exactly the same fashion. There was no extra flammability detected with the treated calico. If you were worried about it, you could experiment with throwing a cup or two of borax powder into the solution before applying it to your tarp, but I've never done it so I'm not sure how it might affect the waterproofing.

Since photobucket broke the internet, I'm not sure how to post pictures. If I work it out I'll reply with some pics showing how it's done.
Don't kill unless for the pot. Don't fell a green tree for a pole if there are dry poles nearby. Study the bush, learn to read its secrets; watch the mason fly building and go to the ant for another lesson... then you'll realise the bush is your friend.
Richard Graves - 1944

Offline Keith H

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Re: Waterproofing Canvas by "paraffinning".
« Reply #1 on: September 23, 2017, 12:49:29 AM »
Good post, thank you for sharing.
Keith.
Two roads diverged in a wood, and I took the one less travelled by, and that has made all the difference. Frost.

Offline wolfy

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Re: Waterproofing Canvas by "paraffinning".
« Reply #2 on: September 23, 2017, 07:45:48 AM »
Buzz.....I'm curious why you don't use the blocks of paraffin that come in the form of canning wax?  It's available in nearly every grocery store in the U.S., but it might be different down there? :shrug:
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Offline buzzacott

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Re: Waterproofing Canvas by "paraffinning".
« Reply #3 on: September 23, 2017, 08:06:03 AM »
Buzz.....I'm curious why you don't use the blocks of paraffin that come in the form of canning wax?  It's available in nearly every grocery store in the U.S., but it might be different down there? :shrug:

Wolfy
I've only seen it in stores here a couple of times and it was pricey compared to candles. It should work as well, if not better than candles. The stuff I saw was pure, almost translucent unlike the opaque white candles.

Keith H.
No worries. I hope it's a useful snippet.

Cheers!
Don't kill unless for the pot. Don't fell a green tree for a pole if there are dry poles nearby. Study the bush, learn to read its secrets; watch the mason fly building and go to the ant for another lesson... then you'll realise the bush is your friend.
Richard Graves - 1944

Offline buzzacott

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Re: Waterproofing Canvas by "paraffinning".
« Reply #4 on: September 23, 2017, 08:22:32 AM »
I worked out that if I upload the pics to my blog I can embed them in posts here :-D


Paraffin candles melted before adding the solvent. The boiling vessel was a galvanised iron bucket and the wax was melted in an old coffee can. which we'll see again later.


Partway through painting the solution onto my japara tarp.


Japara tarp on the clothesline drying out after the application of the solution.


4-man cotton japara wall tent straight after application of the solution


Japara wall tent side on while still wet.


Japara tent as it's drying


Nearly dry... as you can see, it doesn't change the colour of the fabric much at all.


Japara tarp and wall tent out on a two nighter the next weekend.


The same tin of DIY paraffining solution photographed this afternoon - about three years after the proofing pics above were taken. You can store it for years in a sealed container.
Don't kill unless for the pot. Don't fell a green tree for a pole if there are dry poles nearby. Study the bush, learn to read its secrets; watch the mason fly building and go to the ant for another lesson... then you'll realise the bush is your friend.
Richard Graves - 1944

Offline wsdstan

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Re: Waterproofing Canvas by "paraffinning".
« Reply #5 on: September 23, 2017, 12:44:11 PM »
Excellent bunch of photos, Thanks!
A man who carries a cat by the tail learns  something he can learn in no other way. 
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