You shouldn't really have to waterproof a synthetic tent. I am no expert but know a little (which may be dangerous).
Synthetic materials like polyester and nylon have a waterpoof membrane incorporated into the material, layered on the inside. Water should not be able to penetrate this under normal circumstances but the material still has to 'breathe' so it will have microscopic pores. The HH of the material is the point at which water will eventually seep through but in normal conditions this will be very rare.
The outside of the material usually has a layer of silicon which helps with the waterproofing by causing water to bead into droplets and run off, thus the material, in effect, never actually gets wet. This layer also has UV protection.
However, after years of use or extremely prolonged exposure to the elements, the silicon wears off. Usually by then the tent will have started to wear in many places and may well be reaching the end of it's life but if you think it is worth it, you can respray the silicon using Fabsil or Nikwax which, as you said, can be expensive. You may have to repeat this from time to time as it will never be as good as it was when new. There are similar sprays for waterproofing canvas.
You will know when the silicon has worn off because the tent material will start to hold water and look like a wet rag when raining. The rain will no longer 'bead' as it should do. However, it should still be waterproof and not a big problem except it may taken longer to dry the tent when wanting to pack it away.
The tent I presently have was an ex display model and because it had been outside in all weathers the silicon was well and truly gone although it wasn't leaking. It is a 6 man tent and took 3 x 600ml cans of Fabsil at £7 a can to reproof it all. I did get the tent very cheap though and don't expect it to last forever.
Incidentally, you obviously don't spray if it is windy and hold the can just a few inches away from the material (read the instructions). You can buy it in tins and paint it on with a brush if you wish.
I'm gonna take a stab in the dark here, and guess that I know even less than Bob... However, I agree with every word he's posted above. :-)
(Could it be we are both wrong?..... surely not!! )
One thing though, Simun.... Is this the tent you posted about a few days ago? The Eco vango doodah? Was it new or second hand? And more importantly... very importantly... have you actually got it wet, and seen evidence of leaking?
Even if it's second hand, it may still be ok, and many folk on here.... far more experienced than I.... suggest that if the tent doesn't leak, don't waterproof it!!
And if it is leaking, it may be the stitching at the seams, rather than the material itself. If so, there are two ways to deal with that (that I'm aware of!)....
If the tent has been bagged up a good while, the stitching may have dried up (no, I mean really dried up). Pitch the tent, get it soaking wet (rain or hosepipe), (twice, if need be!) and the chances are the stitching will swell, and fill the holes caused by the needle that stitched it. If that doesn't work, there are various sealants on the market, all called "Seam-seal" or similar! This is applied to the leaking seam, where the stitching is.
Obviously, if you have pitched your tent, soaked it, and there is water getting through the actual tent material, then ignore this whole post, tell me to mind my own..... and go ahead with the Fabsil/Nikwax treatment... or bin the tent!!
All the above is 100% right.
After 4 seasons I spray my tents once a year. It won't hurt the tent. If the seams are leaking and the tape is pealing try to take the tape off before seam sealing.
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Quote: Originally posted by Mucker1884 on 15/1/2014
I'm gonna take a stab in the dark here, and guess that I know even less than Bob... However, I agree with every word he's posted above. :-)
(Could it be we are both wrong?..... surely not!! )
Until I bought my latest tent, an ex display model, I would simply have said you don't need to waterproof synthetic tents and doing so was just a waste of money.
However, when I erected it in the garden and it helpfully rained almost immediately, and continued raining for two days, I could see it was looking like a wet rag. Thinking I had bought a tent which was only fit for the rag bag I had to do some research.
Hopefully, by spraying with Fabsil I have managed to salvage it. I haven't managed to get away in it for a proper test yet but it looked ok when it rained again after spraying, and the rain beaded nicely.
Put it up, see if it leeks if so reproof.
We bought a secondhand tent that had been returned.It came from an ebay store and was soaked and mildewed.We treated with milton , dryed and put away.
It rained in like a sieve so when i got it home i did clean and reproof.
Brand new tents are not supposed to leak but if your not sure of its past best to check at home.
Don't forget to leave a review of all tents you've used, for a chance to win fantastic prizes
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Topic: re-waterproofing
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