REPROOFING A TENT (FLY )

[KANANGRABOYD]

Well I have no idea whether or not that this has been talked about on this forum ( I know it has on various other outdoor blogs/forums) but thought I'd add my lil 5 cent Echinda's worth, and hopefully just like I have others will hopefully take the plunge and try this themselves.
I was researching for about 2-3 months before I decided one Saturday to go to Bunnings and get the required products to do this. What am I talking about? - well reproofing a high end tent fly ( PU coated).
The tent I reproofed was a MONT EXTREME DOME - 2/3 person, 4 -Season tent. I purchased this little gem in 1996 I think, whilst I was working for one of the well known outdoor retailers here in Sydney, and got it for what at the time they called "PRO DEAL". That was cost price less 10-15% to staff who worked in stores that sold Mont products. I was "unfortunate" that I received the lesser nice colour tent that they made. It was produced with both a really attractive what I call "North Face" yellow, and also the lesser attractive Aubergine/Purple. I was "lucky" to get the purple. I actually called Neil ( Montgomery) and asked why did I get that colour and he told me it was because " we had a bunch of this ripstop PU fabric, and so made a batch of tents in this colour"- over time the colour grew on me.
I bought this tent for backcountry skiing expeditions in the Australian Alps ( Blue/Club Lake, Jagungal, Shlink Hilton, Gungartan etc). For that it served extremely well. That tent accomodated a number of "unfortunate" ex-girlfriends who I convinced to accompany me on epic Winter backcountry expeditions, all of them had never skied before ( yes I will pay for that!- and I did/have).There were never any secondary/further trips( holidays) with any of them!.
Marketed as a 3 person tent - it is PERFECT as a 2 person tent. One ex-girlfriend even made a fantastic little attic/gearloft for it.
This tent has seen use from the Aussie Alps in every season and condition, to -50c and 100km/hr+ winds/blizzards in the High Canadian and Alaskan Arctic, to lazy 2 week slugfests at the Basin in Pittwater, Sydney over Xmas ( the occupants being my unruly nieces). So as you can imagine, over the last 17 years this guy has seen extreme use in every sense. Although I would have to say that this tent has been one of the BEST tents I have ever owned, it has unfortunately been exposed to horrendous weather - extreme UV at high altitude, long Summer 24hr days in the Arctic, high winds, and probably the biggest killer was having to roll up/pack the tent WET! and leave it in that rolled state in its bag for a few weeks. As a result, the fly over many years started to show delamination of the PU coating from the fly, and the tape sealed seams were starting to peel etc. The inner ( main tent nylon fabric ) - ended up attracting a massive amount of mould from me having to pack away and leave the tent packed up for a period of about 6 weeks hidden in a cache. I also noticed that the floor, was starting to show signs of wear and tear.
So after all of this I had 3 options. 1: Either continue to use the tent until it started to fall apart ( it was already letting some rain in through the fly in heavy rain ), 2: perhaps try and have the fly recoated/replaced ( I know Mont do not make this tent anymore) or I could get Venus to do it , or 3: reproof/recoat the fly myself using either commercial products ( which can cost over $100 or more for a fly that size ) or make my own reproofing mixture.
I chose to do it myself ( DIY/MYOG).
After spending a couple of weeks perusing the forums and net, I decided to go ahead and try making my own batch of reproofing liquid. I watched countless YouTube videos, read many forum posts from BPL, Hammock et al and then last Saturday went to Bunnings ( nope didn't get any Snag sandwiches!), and bought some 100% Silicone and also some Low Odour Mineral Turps ( Diggers Brand). Total cost for 2 tubes of silicone and 1 bottle of turps was about $20. I also bought some foam brushes.
After reading through a million webpages, I decide to just experiment and make my own ratio of "product". Most call for a ratio of 1:5 Silicone/Turps - maybe Franco can provide better ratios and lol... rationales....!
I set the tent fly up inside out, then removed all the tape sealing on the seams that I could, and also washed the fly with normal dishwashing detergent and water, using a mild scouring pad ( one of those green and yellow ones), and made sure it was rinsed really well and all the visible PU material was removed. Then let it dry in the shade.
I started out with what I estimated to be a ratio of 1:3. It was fantastic at doing the seams, so I did all the seams inside and out and let it dry. I then did a water test with the hose and checked the seams - all were 100%.
Next... I mixed up a big batch of 1:4/5 and using a foam sponge brush painted the entire inside of the fly and let it dry. I also did half the floor of the tent to see how it would be- turned out really nice and grippy.
I haven't weighed the tent so as to show how much extra weight I added from reproofing ( sorry Franco )- but I do not care about the weight as it will be a tent that stays insitu at a camp/cache , so all I want it to be is bombproof and waterproof. The tent turned out unbelievable!!!. It really did as good a job as a commercial reproof ( maybe not as aesthetically pleasing) but in terms of actual waterproofing and protection ( the silicone I got had a high UV resistance- very important for tents) - as for those members who do not know - the NUMBER ONE KILLER OF TENTS is UV RADIATION. It will absolutely annihilate your tent fabric over a very short period of time.
So obviously time will tell and see how good this new coating proves against the original - I do not expect it to be 100% as good, but if it is 80% as good and atleast 100% waterproof, then that is all I want.
The other thing I did to this lil beauty of a tent is to wash and clean the tent ( inner). I mixed up some White King Concentrated Bleach ( to know how strong it is you need to look at the concentration of Sodium Hypochlorite)- in this case it is the strongest at 63g/lt. So I mixed up a spray bottle and diluted with water to about 10:1 ( H2O:Bleach), and sprayed the entire inner, paying particular attention to the main areas of mould. I then used a green/yellow scourer and scrubbed the entire tent, then using a garden hose on the strongest "jet"setting, washed/rinsed the inner both inside and out until I couldn't see any bubbles of detergent etc. I then let it dry in the shade. It turned out like new! ( see pics)
Even though I have looked after this tent as best I can for the better part of 17 years, the reality is that after a certain amount of time the coating will eventually peel/delaminate from the fly. This renders the tent pretty much not waterproof, and you are left with a useless fly. Like me you have options.
I highly recommend than anyone that has a similar situation with a tent fly - but is unsure what to do or how to go about reproofing/waterproofing the fly, try what I did. Go on the net and watch and read others posts, and then try yourself. I was fairly nervous about it, thinking either it will turn out crappy, or I will have wasted a lot of money, but the results were great.
I can tell you, if you be somewhat patient and meticulous - you can reproof your tent fly ( or even tent) for a fraction of the cost of either buying the commercial reproofing liquid or obviously replacing the original item.

-50C ON ELLESMERE ISLAND NUNAVUT.jpg (508.09 KiB) Viewed 57646 times

LOWER KOWMUNG CAMP.jpg (203.88 KiB) Viewed 57646 times

mont tent fly worn.jpg (216.71 KiB) Viewed 57646 times

old against new.jpg (258.4 KiB) Viewed 57646 times

mont fly renewed.jpg (272.1 KiB) Viewed 57646 times

[KANANGRABOYD]

and a few more...

old against new.jpg (258.4 KiB) Viewed 57644 times

TENT INNER CLEANED.jpg (106.32 KiB) Viewed 57644 times

[troutboy]

Looks like it turned out great KB you can definately save some cash by having a go yourself.
cheers Jamie

[bernieq]

... painted the entire inside of the fly and let it dry

Why the inside? I would have thought that proofing the outside would
1. reduce the 'wetting-out' of the fly material (presumably nylon) when it rains
2. reduce the UV-induced degradation of the fly.

A pity you don't have weights to compare pre- and post-proofing. It would have been interesting to estimate the /sqm effect.

[Moondog55]

I did this on my old Megamid, from memory it added 200 grams.
It worked very well

[KANANGRABOYD]

... painted the entire inside of the fly and let it dry

Why the inside? I would have thought that proofing the outside would
1. reduce the 'wetting-out' of the fly material (presumably nylon) when it rains
2. reduce the UV-induced degradation of the fly.

A pity you don't have weights to compare pre- and post-proofing. It would have been interesting to estimate the /sqm effect.

Bernie,
Yes I should of weighed fly pre weight - but will weigh it now and post. OK see pic
Did it from inside as that is where the PU coating was delaminating from, but yeah maybe of been better to do outside.
After the entire fly was reproofed I did a garden hose test - ABSOLUTELY 100% dry - not a drop got through!
I used the better part of 1.75 tubes of that silicone so I guess that is the added weight. A single tube weighs 310gms ( entire tube)

[Onestepmore]

Great story
I love the colour!

[bernieq]

I used the better part of 1.75 tubes of that silicone so I guess that is the added weight. A single tube weighs 310gms ( entire tube)

OK, so 1.75 x 310g minus the tubes plus a proportion of the turps (say 75% - assume the other 25% evaporates) = ??? :)

I proofed the seams of my MSR Hubba Hubba a few years ago and that added noticeable grams (worked well though) and the fly could really do with improved rain resistance but I've been apprehensive about adding too much weight. Maybe I'll just have to do it.

[Franco]

Kanangraboyd ,
It worked, so well done !
For anyone else attempting this a few tips.
First do make sure that you use 100% silicone and mineral (not vegetable) turpentine.
next mixing is easier if you add a bit of turp to the silicone and then mix and keep adding. So don't put all of the turp in at once.
Try it first if you can on another piece of the same fabric. Typically the stuff sack is made of the same fabric as the fly.
Just use a corner and see how you like it.
I found that a cloth (a Chux for me) spreads the mix thinner and more even then a brush. A sponge brush might do the same.
You should be able to do the whole fly with less then 200g of silicone.*

* Uncoated nylon : about 1.1 oz per square yard. Silnylon :about 1.4 oz (same fabric siliconised) around 8g of silicone per square yard.

[Moondog55]

I found that the thinner the mix the better and I used a cheap misting spray bottle that I rescued from the recycling bin. From memory I used 2 tubes of silicone to 3 litres of turps and did the Megamid and 2 flys.
I have one more tent to do but I am going to wash it first and it can wait until summer as I intend to do some modifications anyway

[Avatar]

After that bleach washing don't you need to DWR proof the tent inner as well? What will you use for this?

[KANANGRABOYD]

After that bleach washing don't you need to DWR proof the tent inner as well? What will you use for this?

Sorry for delay in reply!.
I ended up just using a can of 3M Scotchguard spray - I had a full can in the cupboard, so used that.

[Avatar]

Best of luck with that 3M Scotchguard. I have used it a few times on gloves and boots and have found it doesn't seem to do much water repelling.
What about using Nikwax TX Direct? I've been looking for the Atsko DWR treatment but all I can find is the Sportswash (at Anaconda and Paddy Pallins) that the deer hunters favour because it doesn't fluoresce.

[byrnesy8]

You can get the Atsko spray from
www.globetrekker.com.au

I have found the spray very effective

[KANANGRABOYD]

Best of luck with that 3M Scotchguard. I have used it a few times on gloves and boots and have found it doesn't seem to do much water repelling.
What about using Nikwax TX Direct? I've been looking for the Atsko DWR treatment but all I can find is the Sportswash (at Anaconda and Paddy Pallins) that the deer hunters favour because it doesn't fluoresce.

LOL - yes I know, I used it only because I had it, but not worried about DWR on inner as I have the fly!. Yes all those fancy washes and sprays are mostly overpriced and underperform.

[Avatar]

Just thought I would check back in on this. How is the fly going? Any peeling of the silicone yet?

[andrewp]

Hi Kangaraboyd,

Was the fly sticky afterwards? E.g. sticking to itself when folded, and/or dirt, sand etc sticking to it.

[jsf1972]

Hi I have an MSR Phantom tent and the seam tapes were cracked and pealing as well as some patches of delaminating proofing on parts of the fly. I cleaned my fly as you described. I put seam sealer on 3 days ago and now when I brush my hand past the seams it just flakes off. Any suggestions? I didn't want to do the silicone knowing the seams weren't sticking. Cheers JSF

[Moondog55]

Is it the original PU proofing flaking off?
if so you have nothing to lose by trying the treatment
With the "Attack" I turned the fly inside out and treated the original proofed side first then after it became touch dry I reversed it and treated again
It is important to double coat before the first one cures so with-in an hour or so
If by accident you used Acetic cure silicon you may need to scrub all that off or did you use a proprietary sealer?

[jsf1972]

I used sil net silicone seam sealer by gear aid.

[undercling-mike]

I used sil net silicone seam sealer by gear aid.

For PU coated fabrics you should use Seam Grip seam sealer, the silicone stuff is designed for silicone coated fabrics.

People are having success reproofing tent flys that were originally PU coated with silicone but there may be a couple of factors in this. One is that the original PU coating may be degraded allowing the silicone mixture to penetrate into the fabric and the other thing is that they are thinning the silicone to get it to work into the fabric better and a thin layer is less likely to peel than a thick layer.

[jsf1972]

ok cool

[Moondog55]

Yes Mike a thinner mix works better, also the existing DWR has normally worn off after a few years exposure [ most people aren't aware that it needs to be redone every season or two depending on exposure] but treating the inside first works better for me because it seems to stabilise the flaking PU
Personally I use diluted silicon for all my seam sealing and I've never had a problem

For reproofing purposes I use a much thinner mix than KANANGRABOYD but usually do 3 or 3 coats so the total is about the same

[Avatar]

Slightly off topic, but has anyone proofed paper maps the same way and has some guidelines for the rest of us? Thanks.

[Moondog55]

NO But I've got another couple of tents to reproof during the next week or three and I can experiment using cheap newspaper and 80GSM printer paper and see what happens

[englishmanbo]

Silicon did not adhere well and peeled. I have just rubbed it all off with my hand. Now will spray inner side with PU outer with DWR like the original coating.

[Moondog55]

Dis you wash ll the dirt off irst?

[englishmanbo]

Washed and dried prior to storage. Didn't wash again for treatment. It looked and felt clean. Dirt may have been the reason but I think it is more likely it did not adhere to the existing DWR. The silicon came off so easily with rubbing.

[Moondog55]

DWR is silicon based in some instance but it can be teflon
This is why it needs to be washed I have found but th DWR is usually on the outside with the proofing on the inside, which is why I treat the inside first

[englishmanbo]

Yes I treated the outside first, do you think it is worth giving it a good wash and treating the inside with silicon?