Waterproofing poncho shelter with silicone and mineral spirit

[fellwanderer]

I want to waterproof my Polish lavvu teepee/poncho shelter and products like Fabsil, although very good, is expensive, costing more than the shelter so was looking at the cheaper option of using clear silicone sealant from cartridges, mixed with mineral/white spirit. I've seen recommendations not to use silicone if the material is acrylic canvas which contains fluorocarbon, this repells silicone making less waterproof. Fabsil contain silicone and recommended for all canvas so its confusing the contradictory info on the internet. So my question is and I hope somone can clear this matter up, has anyone tried using clear silicone mixed with white spirit on their poncho shelter and what was the result.

Atb,

Damian.

 

[Tony]

I've not tried it on a poncho shelter but i have tried it on other things and to be honest it was a bit hit and miss, I've got to the point where I just look out for sales and get some fabsil and store it till I need it. I expect that there's some good step by step instructions and I'm not saying don't try it, but if you get it wrong there's always going to be consequences, I've a 6x6 tarp that's not much use in heavy rain now

 

[Hammock_man]

I have used poundshop clear silicone mastic gel and terps to fix a torn tie out on a DD tarp and it worked just fine. With hind sight I would have "watered" down the gel more but other than that it was an easy task. ( I would add the torn tie out was my mistake not DD's).
The mastic did need a good deal of mixing, maybe a hand drill with some stirrer would help with the qty you would have to use. However it was just Mix , Paint and allow to dry

 

[fellwanderer]

Thanks for the replies, I've seen silicone used on tarps with good results but might have an adverse effect on cotton canvas which becomes more waterproof as the fibres become wet and swell together known as seasoning the canvas. I don't want to ruin the shelter though it cost only £20, its in un issued condition and waterproof at the minute so was thinking more long term. I've read somewhere the shelter shouldn't be treated until its been wet a few times to allow the fabric to season properly. Fabsil is the safe option and might go down that route rather than risk damaging the existing treatment on the fabric.