by fishfruit » Thu 02 Jul, 2015 3:42 pm
Thanks thejungleisneutral, that is sounding pretty promising with the black wattle treatment. It would be interesting to see how things stand up to a couple of weeks of rain but it sounds good enough for me to give it a go at any rate. Going by the weights, it sounds like you ended up with maybe a quarter of the wax out of the original mixture in the tarp. Not a lot of wax for the volume of fabric really. Since as I mentioned, I have particular difficulty with solvents, I am thinking I might try rubbing a bar of wax mixture onto some fabric and ironing it in. Just to help me figure out if my experiments are effective or not, can you give some indication as to how much the treated fabric wets out compared to the untreated fabric? I will probably conduct my initial trials on some old sheet scraps so I wouldn't expect it to be as waterproof as coated japara, but there is no point spending money on fabric until I have a fair idea something will work.
I did successfully make a sample piece of oilcloth without solvents a couple of years ago. I tracked down some solvent free cleaned linseed oil (Allback brand, who I think only had one Aussie distributor at the time), wet out a bit of old sheet with it, and left it pegged out to dry until it was thoroughly cured and then left it out a bit longer to make extra sure it wouldn't self combust and burn the house down. It was fairly waterproof and quite flexible, but I decided that I wasn't sufficiently keen on a full tent like that to go to the trouble of making one at the time. My scrap got filthy pretty quick, which I gather can be an issue with some oilcloths attaching readily to dust.
Would I be correct in assuming that even when proofed as you described above, the japara would need a steep pitch? I had thought of doing a hooped design like the modern tent swags, but I suspect that would be outside of the limitations of the choice of materials and the old fashioned A shape might be the better way to go.