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Seam Seal, again in quantity?

G

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Continuing with recommendations for upcoming tent and tarp maintenance, I will soon have a 4 x 8 foot tabletop set up in the shop and be ready for a seam seal production run, gently stretching and sealing sundry tents flies and tarps.

In for a penny, in for a pound, I might as well do most all of the tarps and tents while everything is staged. That is a freaking lot of seams to seal, and there has to be a better solution than buying a couple dozen little 2oz bottles that will each barely do a single tent, if that.

Seeing as I do not seal the seams very often, the good stuff, whatever that is. If it makes a difference in sealant selection most of the tent fly and some of the tarp material is silnylon. I foresee a week or more of tent flies and tarps stretched out atop the table and sealed, then set up on a sunny lawn while I do the reflective line replacement.

A pint of seam seal would not be too much. Or even a quart, we could have a Bring your tents and tarps seam sealing party in the shop with the leftovers.

Suggestions for a quality seam sealer in larger volume?
 
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You can make your own sealant for silnylon. Get a caulking tube (or 2 or 3) of good quality 100% silicone. Cut it with mineral spirits (I have also used lacquer thinner) until it is the consistence that you want or need for penetration. Use a clean glass jar to be able to visualize complete dilution. I use a small narrow disposable foam brush to apply.

I know you said that you plan on doing it on a shop tabletop. I have done that for the ease of access, but have found that I get better results with either the tents set up, or the tarps hung.
The sealer penetrates better in my opinion when the fabric is stretched as it would normally be. Seems that the needle holes on the seams take the sealant better when opened up, when stretched into normal taut status.

I have hung tarps flat at just above head height, and use a strong headlamp. Makes it easier to see the seams as I seal them. Let the underside seams dry for a couple of days, then flip it over and do the other side.

I have used this mixture to completely re-coat a rain fly for a 45 year old backpacking tent, that the coating completely flaked off of. Put it in the washing machine for several cycles, that stripped the remainder of the flaking coating off. No idea what was originally used as waterproofing. Set the tent up, with the fly in its normal configuration. Used the silicone thinly mixed to paint it, and let it dry in place. Has sealed it and it has worked great now for several years.

The store bought (Sil-nylon) seam sealer is just a flowable silicone. Might as well make your own.
 
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G

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Guest
You can make your own sealant for silnylon. Get a caulking tube (or 2 or 3) of good quality 100% silicone. Cut it with mineral spirits (I have also used lacquer thinner) until it is the consistence that you want or need for penetration. Use a clean glass jar to be able to visualize complete dilution. I use a small narrow disposable foam brush to apply.

The store bought (Sil-nylon) seam sealer is just a flowable silicone. Might as well make your own.

Just for funsies I look at silicon seam sealer on REI.
1.5 oz runs $7. Might as well is an understatement.

https://www.rei.com/product/705425/gear-aid-silnet-silicone-seam-sealer-15-oz

The Coleman water-based stuff is not that much less expensive. I am resting some hopes on this DIY mix; it would be a huge boon to families and folks with multiple tents and tarps, and likewise for Guide folk with gear for clients.

I need to make a hardware store run anyway. Add one caulk tube of good quality 100 percent silicon to the list. I have plenty of mineral spirits.

I am still a little leery of painting a solution containing mineral spirits on a tarp. No reason, just never done that before. I will start with one of the older crapped out urethane coated nylon windblock side tarps, just to see what happens.

Any other consistency, opacity, percentage or thickness proportion for that DIY seam seal mix would be appreciated.

I know you said that you plan on doing it on a shop tabletop. I have done that for the ease of access, but have found that I get better results with either the tents set up, or the tarps hung.


The sealer penetrates better in my opinion when the fabric is stretched as it would normally be. Seems that the needle holes on the seams take the sealant better when opened up, when stretched into normal taut status.

I have hung tarps flat at just above head height, and use a strong headlamp. Makes it easier to see the seams as I seal them. Let the underside seams dry for a couple of days, then flip it over and do the other side.

We have a couple of reinforced 4 x 8 plywood sheets made into sawhorse tabletops, mostly used as banquet tops, but also in the shop when I need a large unobstructed flat work surface.

I just lay one across sawhorses in the shop, lay the tent flies or tarps across the 8 foot length, gently stretch out and clamp down the seams, seal and then move on to the next 8 feet of seam on big tarps. Flip it and do the otherside.

I am not working over my head or worse Oh no, it is about to rain again (now 8 days and counting). Some of the seams on parawing catenary cuts are really awkward to do overhead with the tarp set up, there is nothing rigid on those curves to brush against.

The tarp and fly stuff makes for a good rainy day shop project.

Bathtub tent floors always get set up in the yard on a sunny day and crawled into with seam sealer in hand, there is just no easier way.
 
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I am still a little leery of painting a solution containing mineral spirits on a tarp. No reason, just never done that before. I will start with one of the older crapped out urethane coated nylon windblock side tarps, just to see what happens.

Any other consistency, opacity, percentage or thickness proportion for that DIY seam seal mix would be appreciated.
Mike, I really think any solvent that will cut the silicone would work. It doesn't have to be mineral spirits. Just needs to dry or flash off, leaving the silicone. Haven't noticed any flexibility change in the silicone once the thinner agent had dried.

I learned how to dilute silicone a long time ago from a buddy's father. He was a commercial fisherman and crabber. Always ran his outboards and mud motors without cowls, in all kinds of weather. Always wondered how he kept the electrical systems running in horrible rainstorms, as those were the days of distributors, points, and rotors. Silicone was the answer, thinned with whatever he had laying around worked extremely well. I have also used it to paint around ignition systems on all kinds of stuff; 3-wheelers, 4 wheelers, and my Trooper. Some idiot keeps driving my Trooper off into deeper water than expected.


As to consistency, opacity, percentage or thickness proportion, I just squirt enough silicone into a clean pickle jar, and start adding thinner until it looks right. Sometimes I need it thin to soak into canvas, or a little thicker for more modern materials, as a seam top coat. No formula. Redneck seam sealing here. Put the top on well after use, and if a week later it starts to set up, add more thinner.

I have had it rain once within about 4 hours of application, when trying to get a piece ready prior to a trip. I don't always have everything completely ready. Rain just beaded up, or ran off with no change to the seam sealer. Silicone is not hydroscopic, so really you could probably apply just prior to rain with no detrimental effect.
 
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Very interesting and useful information. I can see a number of applications where this will be of use to me. Thank you.
 
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