waterproofing solution

[tradguy]

Hi
I recently bought two norwegisn knappetelt sheets, they are cotton canvas. However, after an overnight garden-camping test, I noticed that raindrops were soaking into the fabric.
It doesn’t look to me like they are oilcloth, but feel free to correct me.

The photos are the tent, and then the fabric after a splash of water.

 

[C_Claycomb]

Hi,
You haven’t used any question marks. Are you asking how to waterproof better, what people think it is or just stating how they have performed?

 

[tradguy]

oh yes, of course!
Apologies for that, my English wasn’t englishing.
I would like to have some suggestions for waterproofing the fabric, without making it too stiff or heavy.

 

[Longstrider]

If a dribble of water soaks in like that I'd say it's far from waterproof. I'd be looking to get the material dry .. really dry, then have at it with something like https://www.halfords.com/camping/camping-accessories/fabsil-gold-universal-protector-1l-631838.html

 

[tradguy]

If a dribble of water soaks in like that I'd say it's far from waterproof. I'd be looking to get the material dry .. really dry, then have at it with something like https://www.halfords.com/camping/camping-accessories/fabsil-gold-universal-protector-1l-631838.html

Thank you this looks great
Will it change the colour of the fabric significantly?

 

[Longstrider]

Don't know fella TBH. I have a litre of it waiting to be applied to a garden parasol/umbrella thing I bought cheap. Most things like this tend to darken the cloth to one degree or another, but surely that wouldn't be much of a problem with a tarp ?
I'd rather have a dark tarp that was waterproof than a light one that wasn't !

 

[tradguy]

thank you for the tips!
I’m looking forward to having a waterproof tarp

 

[Tengu]

Fabsil is the trick

 

[tradguy]

I have seen Nikwax cotton proof.
Is Fabsil gold more reliable?

 

[Pattree]

I think so.

 

[MrEd]

I have seen Nikwax cotton proof.
Is Fabsil gold more reliable?

Yes, I have had better success with fabsil compared to cotton proof. But they still won’t make it completely waterproof tbh, more ‘water shedding’ but it will still eventually wet out.

Greenland Wax will make it waterproof but it will
Darken it a lot and make it stiffer

 

[Sooty22]

If a dribble of water soaks in like that I'd say it's far from waterproof. I'd be looking to get the material dry .. really dry, then have at it with something like https://www.halfords.com/camping/camping-accessories/fabsil-gold-universal-protector-1l-631838.html

Use normal fabsil, as it has UV protection too, better for tents. Gold is for jackets etc I think, and much pricier.
And yes, Fabsil is awesome for that, it will make the water bead off, but it still does not become impermeable, which is what you want as it will remain breathable.
Make sure nothing touches the inside of the tent; keep things away from the fabric, and the water just beads off harmlessly.

 

[demented dale]

Hi
I recently bought two norwegisn knappetelt sheets, they are cotton canvas. However, after an overnight garden-camping test, I noticed that raindrops were soaking into the fabric.
It doesn’t look to me like they are oilcloth, but feel free to correct me.

The photos are the tent, and then the fabric after a splash of water.

I used fabsil. it is the best thing ever. a silicone based waterproofer that will do the job perfectly. I swear by it, You can get a spray tin or I buy a gallon tin. x

 

[Nice65]

Make sure nothing touches the inside of the tent; keep things away from the fabric, and the water just beads off harmlessly.

This was always drummed into us when we went camping in our canvas tents, touch the inside and it's a miserable night ahead. Worst thing was rolling over in your sleep so your sleeping bag was up against the side.

With this thick cotton canvas I'm reminded of my Flallraven Anorak 8 and how it's not waterproof because it's designed primarily to shed dry snow, and also the great many posts here on the subject of waterproofing without having to Greenland wax the whole thing. Probably for a fabric that isn't moving as much as a jacket, the Fabsil will be ideal.

 

[tradguy]

Traditionally, the tent sheets were lightly waxed. I have heard that 1 part mineral oil with 2 parts wax works well.
Has anyone tried this?

 

[tradguy]

oops I tried posting thr same thing twice but I can’t work out how to delete this message

 

[Billy-o]

There are lots of ways forward. A 2:1 solution of silicone bathroom sealant and paint thinners will work. For the inside. You can use more thinners to get a lighter coat and that may mitigate breathability issues if you go too heavy

I have had no joy with Greenland wax except for adding wind resistance to Fjallraven jackets (note, not waterproofness )

 

[Sooty22]

I think there is a lot of misunderstanding of what cotton fabric can do, heavily influenced by silly claims from manufacturers of 'technical' cotton (Ventile etc) and treatments.
At best, all you'll get is good beading off of water. Even with Ventile, it will wet through and feel damp, although it won't pass water too fast. But even Ventile fails in heavy driving rain, as I think the heavy splashing of water drops cause the pressure locally to exceed the hydrostatic head rating (typically 600-700mm), and end up with a soggy inside.
Normal canvas / other cotton fabrics, like these tents, at best beads the water off, but they will get wet. In heavy driving rain, the inside of the fabric will feel pretty soaked, but the water will still move down the sides slowly, and off to the ground.
Cotton tents work on the principle of having them very taut and with nowhere to pool the water, so it just runs down the side harmlessly. I've been camping with bell tents for almost 20 years now, and they are brilliant, as long as you have NOTHING touching the inside of the fabric, and as long as they are pitched correctly with nowhere to pool.
If you have ANYTHING touching the insides, it will get soaked. And if you have it slack and allowing water to pool, it will pool and drip on you.
So, your tent is likely OK as it is, but it could do with a treatment to help it shed water in light rain. In anything heavier, it will get wet (the fabric), but the water will still just run down the sides, as long as you don't have anything touching the inside!