Today's lesson on DIY Silnylon

**Grapenut** · 07-29-2013, 19:52

OK sports fans...I learned something today. I recently made two DIY tarps from 1.1 ripstop. I treated the first tarp last week and after it cured I put it up in the rain... and it stayed totally dry for hours. I then treated another tarp the day before yesterday. I just put it up in the rain and it leaked quite a bit. Here's what led to the failure of the second tarp...

The mixture I "started with" for both tarps was one tube of the exact same 100% pure, clear Silicone caulk mixed with 2 quarts of low-odor mineral spirits. I used all of the same DIY mixer bit, 5 gal bucket, etc.

While I was mixing the caulk and mineral spirits for the second tarp, I just couldn't seem to get the silicone mixed totally...I kept seeing chunks of silicone, and some were sticking to my drill mixer bit. I had a gallon of mineral spirits that I thought had two quarts left in it when I started...when I saw the chunks hanging around I began to wonder if I put enough mineral spirits in after all. So off to Lowes I went to buy more mineral spirits. I often think while I'm driving and this case was no exception. I began to wonder if perhaps the chunks I was seeing weren't in fact actually the remnants of the lining of silicone I must have put in the bucket when I treated my first tarp. Hmmm...that's probably it I thought. Not knowing how these chunks would look stuck to the outside of my new tarp, I decided to buy more mineral spirits just in case. When I got home I added another pint or so to my silicone brew. Everything seemed ok after that and I even found that the chunks of silicone would peel right off the ripstop after they dried.

What's the moral of the story? If you choose to DIY the weatherproofing on your tarp then stick to the right mixture of caulk to mineral spirits...and consider using a fresh/clean bucket to mix it in. Guess I get to do this one more time! lol I'm just glad the 1st tarp passed with flying colors so that I could keep the faith. It took a bit of time to sew these bad boys!

Cheers!

G-Nut

**Lost_Biker** · 07-29-2013, 20:26

Thanks for passing the lesson on. I'm going to try the silicone/mineral spirits dunk this weekend. I'll make sure the bucket is clean!

**SailingandSuch** · 07-29-2013, 22:41

Interesting!

I have read a little about treating your own ripstop with silicone but decided against it when some people had mixed results. Maybe you have found the/a reason some folk's tarps went sour.

Thanks for sharing your findings.

I think you have had plenty of rain here lately to test tarps in......

**Klaussinator** · 07-29-2013, 23:01

This is interesting . . .

When I DIY'd the silicone treatment for my tarp, I'm pretty sure I didn't use 2 qts of mineral spirits, probably yeilding a slightly higher silicone ratio. My tarp was made from Taslite, and the mixture worked wonderfully. Completely invisible, and 100% waterproof. The only peeling I've seen is on the tieout points which are nylon webbing, and I don't care if they're treated or not.

-Klauss

**hikehunter** · 07-29-2013, 23:35

I have made my own sil-tarp the same way.....you got to mix and mix and mix....you get it to froth a bit and you know you are getting close. I used one and half silicone tubes. When it had cured for almost two days I took the garden hose to it and it worked out great. Now, how do I get that kind of water resistance on my Truck????????