Seam sealing

[WestcoastPete]

Gudday. I'm about to seam seal my new Tarptent Contrail with this:



Can anyone see a problem with this? Last time I did this job I was in the USA and just got the stuff that the internet told me to get there, and it worked very well. The advice I think I've found is that what I have here should be fine. Just thought I'd ask here first though.

Ta!

[simonm]

Does it say 100% silicone on there anywhere?

[WestcoastPete]

Not specifically 100%, it just says silicone sealant. I read here that it could be used for seam sealing, I'm just not sure that thinning it with turps is the right move.

[simonm]

Turps is commonly used.

[WestcoastPete]

Righto, sweet. Will get stuck into it then.

[rolfex]

Hi, I recommend using shellite rather than mineral turps. I have had great success using it. Shellite thins the sealant and makes it spreadable with a small brush, just like turps, but evaporates much more quickly (half an hour rather than several days) and smells better too. Make sure you do it in a well-ventilated room.

[Franco]

That is the turp I use.
For silicone I use the Selleys Roof and Gutter.
That does state 100% silicone on the label (at the back)
Can't really tell from the Parfix MSDS what exactly is inside the tube but silicone does apparently change in composition from one manufacturer to the next.
The other type I have used a few dozen times is the GE II , however I have used the Selleys for over 8 years.
Usually the translucent type is OK.

BTW, have a rug (I use Chux) impregnated with some turp at the ready to wipe up excess silicone or drips.
If you have a sensitive nose then you may need to keep that inside a somewhat sealed container.
The sooner you wipe the better the result

[Ellobuddha]

BTW, have a rug (I use Chux) impregnated with some turp at the ready to wipe up excess silicone or drips.

You gotta be a bit more careful with splashing that silicone around Franco. A rug soaked in turps must be heavy to throw around

[Franco]

yes, my wife kept complaining about my head smelling of turp.
That is why I now use Chuxs

[Strider]

Don't find chux leave a lot of fluff behind?

[walkerchris77]

I was on the turps big time last night.

[Franco]

Don't find chux leave a lot of fluff behind?
Not, for me, when wet.
Mind you the one I use for this job is not used for anything else.

[GPSGuided]

With turp and other solvents being splattered around, aren't they at risk of damaging the various synthetic fabrics? What are compatible and what are not?

[Ellobuddha]

I made up a guide out of soft cardboard.

I just cut a section out of the cardboard just wider than the seam and then paint the diluted silicon mixture on holding the card in place. The cut out section only being about three inches long. I found it was effective in doing it pretty neatly. I saw it on the net somewhere. Works well.

[icefest]

Nylon and polyester seem to be been surprisingly resistant to several solvents. http://rfelektronik.se/manuals/Datashee ... tguide.pdf
Polyethylene is also relatively solvent-resistant.
That being so, I’d try to avoid most solvents (bar water and maybe alcohol) as the risk is just too high with equipment on which my life depends.
Personally I find deet to be frustrating, while it does not attack nylon, residue on my hands does dissolve the handles of my walking poles. I think once my current tube runs out I’ll switch to permethrin, which is just as effective.

[GPSGuided]

Would seam sealing tapes be more worry free?

[Joomy]

Hi, I recommend using shellite rather than mineral turps. I have had great success using it. Shellite thins the sealant and makes it spreadable with a small brush, just like turps, but evaporates much more quickly (half an hour rather than several days) and smells better too. Make sure you do it in a well-ventilated room.

Interesting. Never heard of this before. Seems like a good idea especially considering a lot of campers have Shellite lying around anyway (OK they have Turps too probably).

[GPSGuided]

Was shopping for 100% silicone yesterday at Bunnings and saw the two options. Parfix as above and Selley's Roof and Gutter. One is 40g and the other is 75g with close to double the price. Went with Franco's preference and now ending up with 3/4 of the tube spare after my seam seal job.

[Hiking Noob]

I have no idea about this topic but would neutral cure silicone be a better option? Any chance the acid could do anything bad to the fabric as it cures?

[Franco]

As suggested above , use 100% silicone without additives.
(usually called translucent and has that 100% silicone printed somewhere)
BTW, depending on humidity levels (the higher the humidity the faster it cures) I have had seams dry enough to pack in less than six hours to a max of about 30 hours.

[icefest]

I have no idea about this topic but would neutral cure silicone be a better option? Any chance the acid could do anything bad to the fabric as it cures?

From memory the acid cure releases acetic acid (vinegar) which theoretically can dissolve nylon at high concentrations. Some use it without problems though.. I'd probably avoid the stuff.

[Moondog55]

You can only thin neutral cure silicon with solvent. The acid cure silicon can't be thinned effectively at home I have found. Roof and gutter silicon is probably the most used because it is formulated to be the most flexible.
Shellite works very well as does any mix of mineral turpentine and Shellite

[Orion]

You can only thin neutral cure silicon with solvent. The acid cure silicon can't be thinned effectively at home I have found.

Are you sure? I think I've thinned acetoxy cure silicone with mineral spirits before. I could be misremembering though. It's been a while.

[Moondog55]

So have I; but it peeled off in a very short time, which is why I said "effectively", thinning it seemed to do something to the stuff and it didn't stick all that well to the tent I used it on.
Unthinned it is a very effective glue tho and I'm still trying to get some out of a pair of pants.
However to be sure i just Googled the question and 3-M do mention thinning acid cure silicon but I couldn't find the thinner named so I would assume that whatever solvent they say can be used to clean up would also work as an effective solvent for thinning purposes. Perhaps in the case I mentioned the substrate wasn't as clean as it needs to be for an effective bond, any sealing does need a clean substrate [ or a porous one? ] I didn't wash the cotton duck and it worked on that

[GPSGuided]

Looking around on the subject via Google, I note the quantum of silicone applied by people ranged from a raised strip of cured silicone to the virtually imperceptible, due to an immediate wipe down following the brush stroke on highly thinned out solution. Don't believe more is better but how little is enough?

[Moondog55]

Talking to Franco on the week-end his opinion is that it should be absolutely minimal, when I reproofed my Moss Pentawing tarp I think I diluted 100:1 and it worked well

[Orion]

100:1?

That sounds like a homeopathic tent sealant.

[Moondog55]

That was all it needed, after all Bill Moss made stuff that was intended to last a long, long time and that dilution did it. I simply diluted what was left after doing my Megamid with another litre of Shellite rather than let the last few hundred millilitres of solution go to waste
But the first solution was 300 of roofing silicon in ~4 litres of a Shellite/turps mix

[GPSGuided]

100:1 dilution of 'Roof and gutter' with turp would virtually be just watery turp consistency. Way too watery for convenience. But can see how well the solution can work through the sewing thread and those stitch holes. In reference to Franco's 'absolute minimum', I would say that his Youtube video on the subject was still a bit away from absolutely minimum. Saw another Tarptent video and the consistency was much thinner. Virtually invisible after the wipe off.

[Franco]

We are talking about two different applications (!) here.
1)Seam sealing :
dilute the silicone to a virgin olive oil/ baby oil consistency. (so runny but not overly so)
The idea is to get the silicone to fill the holes around the stitching .

2) proofing or re-proofing a tarp or fly.
For example the Moss tarp Moondog has.
This is to give a waterproof coat to the fabric. It needs to be much thinner than for seam sealing.

Atsko and other brands (McNett) sell a spray version typically with less than one ounce of silicone inside the 250ml can .
That is enough to do a double tent.

BTW, yes at TT USA they use a thinner version than the one I use.
Sometime it is hard to tell their work (except against the light) , you can see mine , still it is thinner than most.