Seam Sealing a Tarptent

[Ryan C]

I recently got a Tarptent Moment and need to seam seal it. The weather here is going to be in the 50's tomorrow so it will be a good day to do it. This will be my first time sealing anything.

I have the GE Silicone II that is recommended but need to select a suitable thinner. I do not have a bottle of mineral spirits and cannot justify the cost for only a few ounces.

From what I have read, Coleman White gas can be used as a thinner. Will this harm the Tarptent? Could lacquer thinner be used?

Any advice would be appreciated.

[Brett Rasmussen]

Sorry I can't answer your question about mixing with white gas. I've only made seam sealer with mineral spirits. It is initially expensive if all you need is enough for the Moment. I find that I can always use the sealer. Before I started making my own I would always be buying just one more tube of SilNet thinking it would be the last one. About 10 tubes later I would have saved a lot of money if I had made it from the beginning. If I had some white gas I would try it on some scrap fabric, but I don't use white gas. I did try mixing silicone with denatured alcohol. It would not even mix.

If the weather does not turn out ideal you can always do it indoors. I don't think I have ever even seam sealed anything outside. The heat and dry air found inside during the winter sure does speed up the drying process.

[Ken Thompson]

Use Permatex flowable windshield silicone. Available at your local auto parts store for around $5. Comes with an applicator tip, and needs no thinning. Thin like syrup. Works great. I thought the Mcnett stuff was still too thick to apply easily.

[Charles Grier]

For almost all of the silnylon sealing I now do, I don't dilute the silicon sealer at all. What I do is to "load" the seam by pulling it "apart" or open for a short stretch and then, with a dab of sealer on the tip of my index finger, I smear a thin layer on the seam. It helps to press hard to squeegee the sealer into the thread as well as possible. With practice, you will be able to spread the sealer on a seam and leave a sealer strip about 1/2" wide centered on the sewing. It takes a bit longer to do it this way but you don't wind up with a lot of smelly thinner to deal with.

If you can get help with spreading the seams, the job goes much faster. Just don't let two recently sealed stretches of seam bond together; it's the devil getting them unstuck after the sealer cures. And, practice doing this on places that won't show to get the feel for the job.

[Diplomatic Mike]

I would always dilute it, as the sealant can tear if too thick. Thinned sealant penetrates better too. Good BPL arcticle HERE

[Bill Poett]

I just sealed my Moment yesterday and for ascetics, ease of application and functionality it really is worth the extra effort to dilute the sealant.

Ps enjoy your Moment, had mine out in a nasty storm last night and it was a palace ;0)

Bill

[Ryan C]

Looks like I may end up getting a container of mineral spirits.It could get expensive if I ended up using SilNet all the time for future use. May as well do it right the first time and have everything I need if other things need sealed.

I don't like the idea of having a blob of silicone just running down the seam. It seems better to have a thin solution seep in to seal the seams and it looks much better when done.

Bill- Glad to hear it weathered the storm! The first time I set mine up was in a mild snow storm, it was great.

Thanks to all for the useful comments!

[John Whynot]

Be sure to get the odorless or deodorized mineral spirits…

[Brett Rasmussen]

To mix my own sealer I start with a full caulking tube and empty out about 1/3 of it into the trash. I then remove the plunger in the back of the tube and mix the mineral spirits directly into the tube. Mixing can be done with a paint mixing stick or with a shish kabob stick. I then put the plunger back on. There will be an air pocket at the rear near the plunger. To get rid of it place the tube upright until it migrates to the tip.

For storage I just use packaging tape tightly sealed over the tip of the tube. The sealer in the last inch or so of the tube will become solid, but most of the time I can pull this out. Some times it is necessary to cut the tip back a little to get it out, but I usually start with an opening on the smaller side.

I never measure my portions of silicone and thinner. I just add until I like the consistency. But then I'm the same way with cooking.

I can see how it could be easier to just mix in a different container and then add the mixture to a large syringe, but I prefer working with a caulking gun. Also it is nice to have a whole tube of premixed sealer on hand.

[Roger Caffin]

> Use Permatex flowable windshield silicone.

Good stuff.

Cheers

[Ken Thompson]

I thought my post was invisible. Why thin something when what you are looking for is right there.

[David Lutz]

I read it, Ken….and took it to heart. Your work here is not wasted!

[Sam Farrington]

Ken, I read it too, and thanks for the the picture to help me spot it in the store. Will definitely give it a try, instead of the stove fuel + silnet I have been using.

[Ryan C]

I was not able to seal the tent today. Comments on here have me debating on what method to use though. Brett's method of using a caulking gun is interesting

Tarptent recommends using the mineral spirits and GE II silicone. It seeps into the seams, dries quickly, and looks clean and hardly visible when done.

In regards to Ken and Roger's recommendation of Permatex, how well would it flow into the seams? Would it be better than GE II thinned with spirits? Would it dry clear and clean while being hardly visible?

I am still leaning more towards the thinned GE II silicone method right now since it is what Henry Shires recommends.

[Henry Shires / Tarptent]

>How well would the Permatex flow into the seams? Would it be better than GE II thinned with spirits? Would it dry clear and clean while being hardly visible?

> I am still leaning more towards the thinned GE II silicone method right now since it is what Henry Shires recommends.

I have zero experience with the Permatex stuff but if it works for others I'm sure it's fine. I'll pick some up and give it a try at this end.

-H

[Ken Thompson]

It flows very well. Hence the name. It has the consistency of syrup. With the applicator nozzle you can have excellent pinpoint application. Dries clear. Also being in a metal tube, you can suck some back in by squeezing the tube sides if you get a blob, which you shouldn't. Try it, you'll like it.

[Roger Caffin]

> Permatex, how well would it flow into the seams?
As Ken said, it is much thinner. It is labelled 'flowable' for this reason.

I prefer it over the diluted caulking gun stuff because the latter always goes off a bit fast once it has been mixed.

You see, the silicone usually cures by absorbing water, and almost any industrial solvent contains some water. So as I sit there stirring like mad to mix the thinner into the silicone, what I am actually doing is adding water to the silicone and making it cure … mumble!

Also, you know how the stuff in one of those caulking guns usually cures before you have used half the contents – within a couple of months? Well, Permatex (and some thin Italian stuff I picked up in Courmayer in ItalY) come in metal tubes and seem to last after opening for years!

Yes, Permatex dries clear. Visibility – depends on your skill in applying I think! :-)

Cheers

[JR Redding]

I tried the Permatex stuff last summer on a tarp. I found it to be too thick for my tastes.

Latest Tarptent was sealed with this – http://www.lowes.com/pd_24950-72643-MWPCLR_0_?productId=3066021

All I used on a Rainshadow 2 was one tablespoon of caulk. I like using a thinned concoction because I want it thin on the seams but thicker on the floor to help with the non-skid. You can accomplish this by using a good thin solution (1 Tbsp caulk to 2 tbsp thinner) to do the initial seams then letting sit for a bit for some of the spirits to evaporate off before doing the non skid floor.

[David Lutz]

As a sidebar – Do you want to seal the seam on the inside, outside, or both?

[Ryan C]

This thread is getting interesting. I may hold off on sealing the Moment since we are all learning something here.

Henry: What a fast reply! You must have some kind of alarm that goes off every time there is a Tarptent thread. I would be interested in what you find out since you are the Tarptent expert.

Ken and Roger: Thanks for the useful info on Permatex. It sounds like thinning the silicone can be frustrating.

David: I plan to seal the outside only based off what was read on other forum posts. Having water blocked from the outside and the threads thoroughly coated with "thinner" silicon seems to be the way to go.

[Joe Clement]

I tried the Permatex last week because I was trying to seal my Moment indoors, and didn't have a mixer with me. Gave up after one seam, too thick for me. I usually mix a batch about 4 to 1, then do a second batch about 3 to 1, and paint the seams. It's too easy. If I mix to much, I'll do some inside seams on occation.

[David Lutz]

Could the apparent difference in viscocity have something to do with ambient temps? Sealing something this time of year vs. summer.

[Joe Clement]

It was pretty warm in my apartment. Either way, this is a 1 hour job. Not exactly rocket science.

[Andy F]

GE now has two types of silicone II caulk. One is mildew-resistant for bathrooms and dries faster, and the other is more resistant to UV and freezing for windows and doors. The window/door caulk seems better suited to tent and tarp seam sealing. I haven't field-tested the window/door caulk performance, but I did use it diluted 2:1 to seal some mid-panel tieouts I added to my silnylon tarp. It worked great, and it seems to dry faster than the old GE Silicone II.

Be sure to get the clear caulk. ;)

GE Silicone II Window & Door

[Ryan C]

Andy, I was not aware there were two kinds of GE silicone II. I have a tube of the BioSeal mold/mildew resistant that dries clear. Hopefully it will still work well.

Joe, did you use thinned Permatex or some other sealant thinned down on your Moment?

If I do seal it soon, it will have to be while it is still warm around here in the high 40's/low 50's F.

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