DIY Sil Coating

Discussion in 'DIY & MYOG' started by Graham, Aug 5, 2017.

  1. Graham

    Graham Thru Hiker

    Ok...so if I get 2 decent days in the next couple of weeks I'm going to try applying my own coat of silicone to some uncoated ripstop nylon :eek: "Yes, but - why????..." Let's say I have my reasons which I'll explain at some later point.

    I'm sharing this piece of whimsy in the hope of some collective advice/alternatives and also for some general jollity at my expense :D

    The proposed Modus Operandi:
    1. Take one 90% finished myog hexagonal tarp made of uncoated ripstop before any mid panel tie-outs/lifters are added. Any reinforcements I will have added at this stage will use already coated material.
    2. Pitch the tarp outside where it'll get the glorious UK August sun for most of the day.
    3. Plan is to apply the equivalent of 0.2oz of silicone per square yard, half on one side, half the other. The tarp will be 6.5sqm so that's 22g of silicone each side according to my maths.
    4. Weigh out 22g of silicone into plastic container with lid. Add (by volume) ~30 times that quantity of low odour White Spirit. Stir then seal with Clingfilm put on the lid and shake thoroughly to mix.
    5. Apply to tarp using a cheap foam brush. I'm expecting this stage to be pretty darn quick and I'll make an eyeball judgement after the first couple of long brush strokes if a 30:1 by volume mix is going to give a good, even coverage.
    6. Leave to dry outside for 8 hours plus, then hang the material in garage for 10 days to cure.
    7. On the next available decent day, repeat above but for the other side on the fabric.
    8. Complete build and enjoy results (in my dreams.....)
    The alternative is to apply silicone to the raw material before cutting and assembly but I'm using a simple pattern and I'm reasonably confident in the outcome so I'm going 'all-in' and just coating the fabric I use.
    All the above sounds protracted but I reckon the mixing and application of the silicone mix will take < 30 minutes.

    Has anybody done this before and/or got any wise words to pass on?
  2. Fair Weather Camper

    Fair Weather Camper Ultralighter

    Graham - you really don't have to explain / justify any of the above, to anyone...

    It can all, safely be filed under..

    "A man's gotta have a hobby" :)
    Last edited: Aug 5, 2017
    Graham and Meadows like this.
  3. Gadget

    Gadget Section Hiker

    Another way I've used;
    • Make up a thin mix in a big bucket with a lid.
    • Bung the whole lot in and put lid on.
    • Shake like billy-oh.
    • Open up bucket, and with gloves on, squeeze and work the excess off, making sure all areas are covered and excess squeezed back into bucket.
    • Go and pin out tarp taut to dry.
    • Repeat as many times as you think necessary
      (you may be able to use leftovers in bucket, but be careful it hasn't started to go lumpy)
    Graham likes this.
  4. stormin'

    stormin' Ultralighter

    As in this video.
    Graham likes this.
  5. Enzo

    Enzo Section Hiker

    I've had a go doing myo sinylon.
    1, mixing is not easy, imho shaking won't do it, you'll have to make an agitator ie stick in a drill with flappy bit on end.
    2, getting 22g per m2 will be near impossible. It's not a precise art, I think the best way would be to soak as per Gadgets suggestion and then use a squeegee to force in to the fabric and remove excess. A hot August day won't be your friend here as you want to extend the time you have to work it.
    3, good quality silnylon is £6/m so I gave up, hope you have better luck!
    Graham likes this.
  6. Meadows

    Meadows Ultralighter

    Good luck Graham. I've no experience but will be watching with interest.
    Graham likes this.
  7. Graham

    Graham Thru Hiker

    or three....:D

    More than likely I'll be able to manage that - unfortunately the requirement is for 22g of silicone for each side of 6.5sqm of fabric :rolleyeses:

    @Gadget and @stormin' - Excellent, my missus will possibly fly off the handle but that approach increases the 'fun' factor no end.
  8. Fair Weather Camper

    Fair Weather Camper Ultralighter


    So long as, your dear lady wife is totally cool, with being attached to said drill handle....



    Have to say; she does sounds like a sporting sort.... :)
    Last edited: Aug 7, 2017
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  9. Graham

    Graham Thru Hiker

    Didn't go with the drill approach, sporting sort or not :redface: ....

    So, an update from the Hobbyist on this mad idea:
    • Pitched tarp in ground mode, let it rest in the sun for half an hour then really cranked it tight
    • Weighed 27g* of Diall clear silicone into one of those 500ml HDPE soup containers then in true Hobbyist fashion rounded it up to 30g by weight
    • There looked to be roughly 20ml of silicone so I added about 200ml of Diall White Spirit gave it a quick stir, put some cling film over the top, put the lid back on and gave it a proper shake. When that was mixed up I added another 200ml and repeated, then finally topped it up to 500ml, so about a 25:1 ratio. I've done this mixing technique before (for a groundsheet) and it thoroughly mixes the silicone.
    • I brushed the silicone/white spirit solution onto the tarp, applying it in quick horizontal brush strokes working it in quite firmly. I found it helpful to work on one quarter of the tarp at a time so I could keep an eye on how much solution I was applying. As a bona fide gifted amateur, the first complete coat used 250ml, half the volume. Quite a lot had wetted through the uncoated fabric. Any areas with excess solution I just brushed over. This step took about half an hour.
    • I let the tarp dry for an hour or so - during drying it looked horrible with streaks and patches everywhere
    • A second coat was applied with vertical brush strokes, working the solution into the fabric with firm brush strokes again. As a guide to even application I aimed to get a consistent colour for the fabric which goes much darker when the solution is applied. The second coat only used about 200ml.
    • I let the tarp dry outside for about three hours until it was touch dry and then hung it inside the garage to 'cure' for 2 days. I've had the tarp out again in the sun for an hour today and plan to give it another 5 days of curing.
    It seems like the silicone has bonded to the material and now it has dried it doesn't show any brush marks or patches. Remarkably consistent in fact and it feels like proper silnylon. I'll see how it looks before turning it inside out and repeating the above process.

    For the 3 of you that are even remotely interested in this geeky madness :geek: I'll let you know.

    One quarter at a time...

    20170811_100452.jpg

    The mix

    20170811_101214.jpg

    Earlier today after two coats and two days of curing.....it looks ok

    20170812_134941.jpg

    * Got my measurements wrong, tarp was 7.8 metres square
  10. edh

    edh Thru Hiker

    A veritable Pollock.

    With an i :)
    JKM and Graham like this.
  11. Graham

    Graham Thru Hiker

    Thanks...although the archetypal Hobbyist wouldn't give a toss for a paper cutter's opinion.

    If it works it'll be a complete Fluke.
    cathyjc, Fair Weather Camper and edh like this.
  12. Shewie

    Shewie Administrator Staff Member

    That looks like a success Graham
    Graham likes this.
  13. Meadows

    Meadows Ultralighter

    That's great info and a good looking tarp.
    Graham likes this.
  14. Graham

    Graham Thru Hiker

    Thanks both.

    It's a 340cm long by 240cm wide hex tarp with a 15cm ridgeline catenary. If the next coating of sil works and it passes the rain test, then it'll form part of a basic and very cheap myog hammock setup.
  15. Meadows

    Meadows Ultralighter

    What's the tarp material?
  16. Fair Weather Camper

    Fair Weather Camper Ultralighter

    Looks marvellous Graham, well done :)

    And still a whole 'nuther side to do!
    Oh the joys of retirement...

    I can only dream of having so many free acres of time, for such gloriously guilt free, pointless noodling:rolleyes:


    Sir I salute you :thumbsup:

    Take no notice of @edh he, like me, is just plain ol' jealous... But perhaps for differing reasons..

    Fervently awaiting the next exciting installment.... Abstract Impressionistic or no...
    Graham likes this.
  17. Graham

    Graham Thru Hiker

    I owe thanks to you for that! It's from this eBay seller, the same one you recently bought fabric from to make a hammock :thumbsup: I got 10m of the Khaki 140cm wide fabric, £16.50 with free p&p. I used just over 3m of the fabric for a hammock and most of the rest for the tarp. It's really high quality fabric and you can't complain at that price per metre.

    :hilarious: Dream on....100% guilt-free noodling it certainly is, although two clarifications are needed: I'm not retired (though heading in that direction) and it's not pointless noodling :biggrin:

    A given ;)
  18. Fair Weather Camper

    Fair Weather Camper Ultralighter

    You're quite right Graham; no offence taken one hopes; there is, of course, no such thing as pointless noodling ; it's all fabulous ; mental health boosting, spirit lifting ; good for the soul; creative noodling :angelic:

    (with the 'added fun' of some solvent abuse thrown in....:confused:)


    Everybody should make more time for it ...:joyful:
    cathyjc and Graham like this.
  19. Meadows

    Meadows Ultralighter

    You are already putting my thoughts in to action there Graham, this is why I was so interested in your diy silnylon.

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