Sealing dry bags?

[Outdoordude]

Yesterday i finished sewing 8 dry bags.
I took them into the workshop to seal them along with another 4 id made previously.
I proceeded to mix up some home made seam sealant with some silicone sealant and white spirit. (i got the ratio right with about 2:5 silicone:whitespirit)
So today i tested them to see if they were water proof. I filled them with water.
every one of them leaked. Some worse than others.
Im going to give them another coat over the seams - is this usually the case?
Have i missed something in sealing them?
What i did notice was that none of them leaked at the straight down seam and always round the bottom.

Thanks for your help
Jacob

 

[Andy BB]

Was it the seams or material that leaked - a decent silicon sealant/white spirit mix is normally totally impermeable? Was the silicone/white spirit mix a thick slurry, or was it thin and watery - the former is the way to go!

 

[Outdoordude]

it was quite thin and watery. so should i add more silicone?
It was the seams that leaked.

 

[Andy BB]

Even thin and watery shoulden't leak - unless it was REALLY thin and watery! However, make it up into a thickish paste, and you should be fine. I seem to remember a Seekoutside video that dealt with seam sealing on their tents - ditto Kifaru. I'll see if I can find it.

 

[Outdoordude]

i have watched the kirafu video but ill watch it again.
I might add a bit more silicone then.

 

[Andy BB]

http://www.youtube.com/watch?v=LB_l5rd-CoM

 

[Outdoordude]

http://www.youtube.com/watch?v=7zd5mwn0NgU
heres the kirafu video

 

[Outdoordude]

thats what went wrong i didnt have it as a slurry i had it as a water. Try again lol

 

[Andy BB]

Best of luck! I looked at both of those videos when I got my new Seekoutside 8-man tipi. Slight difference in techniques between the two - Kifaru use a slurry, whereas SO use it a bit thicker. I'm guessing either works!

Having said all that, I haven't bothered sealing mine at all, and despite some heavy snow and rain, it has yet to leak anywhere.

 

[Teepee]

A point to note with thinning silicone sealant is it weakens it. The more thinners added, the weaker it gets.

I don't use silicone on anything unless its silicone treated, then its the only thing that will stick. I much prefer a Polymer based product like McNett seamgrip, Soudal fix-all or similar building sealant. It sticks much harder and if it ever has to be replaced, the stuff you stick over it will adhere properly. Once you have used Silicone, you are stuck (sorry) with it for ever.

 

[Outdoordude]

I redid all the seams with a much thicker paste. More like the consistency of yogurt.
I tested them this morning and they all still leaked. Less this time. I can re seal them again so im going to leave it at that.
Theyre going into a big alpkit airlock xtra which will hopefully keep the water out and if water does get in then stuff getting wet will hopefully be kept to a minimum.

Pete - the reason why i didnt go with mcnett seamgrip is because it was so darn expensive and i havnt got a huge amount of money.

Thanks
Jacob