Contact glue tent repair

Contact glue for repairing and waterproofing tents and adventure gear. This post uses examples of repairs/improvements made to two beautiful new Wanderer gazebo tents. They were made from some wonderful materials, but unfortunately, they were poorly put together*.

Note*: To be fair, the seller did offer a refund or replacement. They also pointed out that (in the fine print) they were not meant to be used in rain or wind. Why would the seams be taped if they were not meant for rain? We chose the replacement (because we desperately needed a new shelter) and the same or worse defects were found in the replacement.

[Add a photo of the two tents set up together when available]

Background to my exploration of this contact glue

My interest in flexible glues started with the use of RTV silicone rubber to join silnylon (nylon fabric that had been impregnated with silicone rubber during its manufacturing). It was the only type of glue that I could find that would strongly glue silnylon. My post: Silnylon Glueing is about the many applications of this glue to DIY adventure gear making and repair when using silnylon.

Next, I discovered that the silicone rubber glue also worked well with many other non-silicone rubber such as cotton, canvas, nylon pantyhose material, Noseeum netting………. and the list goes on.

My love affair with silnylon as a DIY tent material faded because of wet stretching and infernal internal condensation issues. An uncoated polyester umbrella fabric became my preferred fabric for making tents as it eliminated these two silnylon downfalls and is reported in my post: DIY Breathing Polyester Tent For Backpacking.

Unfortunately, this magical uncoated polyester fabric did not glue well with silicone rubber. Luckily, I accidentally found an online source of mystery flexible glue that bonded well to the polyester. This was reported in a post: Glued Repairs Of Adventure Gear.

A little later, while on an extended fishing base camp, our brand-new commercial tents (3*3M) sleeping tent with walls windows and door and 3*4.5M kitchen/dining area) started to leak in even mild rainfall. The seam tapes started to fall off, some stressed seam stitches started to pull and one tie-out tab started to rip the adjacent fabric. This was not a good start for these new tents.

As a trusty old ‘Mr Fix-It’ I had some of my magic glue (as described above) in my repair kit. I also had some strips of my polyester fabric and DIY gear made of uncoated polyester. The fabric could be cannibalised to do some repairs. The magic glue did seal some rain leaks along the seams. However, when I glued on a test patch, I was surprised that it did not bond well to the particular polyester fabric of the new tent. “Test patches could be pulled off with some effort.”

I assumed that the new tents’ polyester fabric had a DWR treatment applied. This was probably preventing ideal bonding, as I expected with my uncoated polyester fabric. A quick and desperate visit to a $2-shop provided us with another glue that could fix our new leaky tents.

I purchased two 20ml tubes of flexible contact glue. They were very similar contact adhesives/glues with different brand names.

Upon closer examination and sniffing, my intuition about these flexible glues was correct and they were typical contact glues made with rubber dissolved in a toluene-based solvent. They were similar to contact glues that I had largely substituted with safer alternative glues as described above. They had a very thin texture that I think allowed them to penetrate deeply into the fabric surfaces.

Note*: Toluene is very flammable and can cause adverse health effects. It should only be used in a well-ventilated area away from flames or sources of ignition. I would also suggest that its use be kept to a minimum and only should be used when no other safer glues will do the job. “In previous glueing posts, I have consistently encouraged the use of alternative glues without toluene solvent.” Nevertheless, the above information indicates that toluene is “…….a common solvent for products such as paints, thinners, and glues……is found in small amounts in gasoline.” So by my assessment, careful sparing use, when justified, should do little extra harm.

As a side comment, in a previous life, my laboratory would have an OHS shut down if the slightest sniff of toluene was detected and the fire brigade would have been called. On the other hand, the painter in an adjacent room could be allowed to work all day breathing in toluene from his painting, but at least smoking was eventually banned.

Tent repairs with contact glue

Initial testing of the contact glue bonding. I eagerly started by glueing a test square of my uncoated polyester fabric to the slightly damp tent. Such contact glue gives the best results by coating both surfaces and quickly rubbing or screeding the glue deeply into the fabric. Then the glue should be left to become tacky dry before pressing the two surfaces together. I waited for most of the residual toluene solvent to dissipate while I had a cup of tea and contemplated the order of priority of the many repairs that may ensue if the glue bond was strong. “I was also happy to know that the shop had plentiful stocks of these little tubes of contact glues.”

Very quickly the glue bonding became strong and I knew that it would get stronger with time as the last traces of solvent evaporated. The glue stayed very flexible while imparting a lot of extra strength to the fabrics. I could see that it would make any stitched elements (such as tie-out tabs) so much stronger and much less vulnerable to ripping.

This super strength came at the expense of making it very tough to push the sewing needle though. This was in contrast to the other glues that I have reported on thus far. However, from experience, such sewing toughness equates to the supper strength of the sewn attachments. The fabric laminates and the adjacent attached fibres are all bonded to each other and provide mutual support.

Sealing short sections of seams. I started to repair the larger tent canopy (3*4.5M), under tying conditions. It was done, as a matter of urgency, from the underside of the tent and sometime during rain. I easily applied the glue to leaking stitch lines along the sewn seams just where the seam taping had failed (partially delaminated). I used a wet finger to screed a small amount of the glue along the seam and into the stitch thread. This sealing stopped the rainwater leakage. This screeding with water and fabric dampness did not seem to impair the bonding of this contact glue.

Note: Further reflection on the above photo suggests that the failure of the bonding between the tape and the tent happened when the silver tent coating peeled away from the dark polyester tent fabric. In other words, the failure is, in part, due to inadequate bonding of the silver coating to the base polyester fabric. In my experience, with glueing various silver coated polyester fabrics, I observe that thin contact glues start to dissolve the silver coating. This may account for the success of these thin contact glues and the poorer performance of thicker contact glues that will be discussed later.

[Add a photo of the dissolved silver coating on a strip of silver coated polyester]

Sealing of entire seams. With time, there was more tape delamination and some seam tape started to fall off entirely. Consequently, I used the glue to seal some entire seams, after removing the defective tape.

Direct sealing of untaped tent seams. The smaller of our new tents (3*3M) had no tape on the seams. In heavy rain, these seams leaked a little, so I eventually sealed these seams from the underside of the tent. The smear of glue is difficult to see (in the photo below) but it stopped the leaking.

As an additional precaution, I also applied the contact glue to the outside of the seams. The glueing shows up much better on the darker fabric surface in the photo below.

Applying new seam tape. If the direct seam sealing should fail in the future, the seam could easily be covered and sealed with a long strip of tape made from my unproofed polyester umbrella fabric. I experimented with glueing on a short length of my DIY seam tape that was cut 30mm wide from my (light) polyester tent fabric using a hot cutting knife. It was glued in place on the inside of the tent. I think the matching silver finish of both fabrics made the repair look quite ‘fetching’. “Now there’s an old-fashioned adjective that can keep you out of trouble when giving a compliment in these days of new feminism.”

Such retaping is unlikely to be needed, but the next time I use the tents I will go prepared with plenty of long cut strips (30mm wide) for this contingency. I will also include some offcut strips (and glue) in my lightweight backpacking repair kit so that I can hot cut patch pieces (with a campfire heated knife) to make repairs.

Time to talk about hot knife cutting. For those of you who sew with an ordinary sewing machine, you will be painfully aware of the issues of managing cut fabric raw edges fraying and pesky fine loose threads that invade your sewing area and vacuum cleaner.

I used a hot knife cutter for the repairs and improvements done in this post. It leaves a perfectly sealed low-profile edge for glued tapes, patches, tabs etc.

The hot knife cutter is one of my best sewing tools for making DIY adventure gear. I wish I had one many years ago. It eliminates the need for hemming to stop fraying, although I still do hemming for additional strength. If I do use hems, I usually glue them first to make the sewing easy. When sewing is required I often use glue to hold the work together (instead of pinning) and it makes the sewing much easier, pleasant and accurate. The hot knife can even weld fabrics together to prepare for sewing complex seams. For more information on adventures in hot knife cutting please see my posts: Hot Knife Cutting And Welding and Hot Knife Welding As Preparation For Easy Sewing Of Tent Seams.

Replacement corner tie-out tabs attached with contact glue and stitching. The original tent tie-out tabs were dreadful. “The webbing had the strength to tow a light car. Unfortunately, they had a contact width of ~10mm with the tent fabric. Each tab would have been lucky to have three or four ordinary seam stitches holding them into the seam. There was not even any backstitching. One tab already had started to rip the adjoining tent fabric! “

I made an alternative wide rectangular tab from my uncoated polyester umbrella fabric. Starting with a 100mm wide strip, the rectangle was folded and glued with wide hems on opposing sides that met in the middle, making them double have a double thickness. Then at both ends, smaller hems were folded and glued with a width that approximately equaled to the tent seam width. These hems were glued together to form a strong tab with a thick web that could be attached to the tent seam. This web provided eight glued laminates of fabric at the critical load-bearing corners when attached to the tent seam.

I cut off the tents’ pathetic tie-out tabs. Then the wide alternative ones were glued onto the tent over the remnants of the original tie-out tabs. After the glue had cured the patch was also sewn through the original tent seam allowances. “I hope the photo below will explain this better than my words can.” This attachment was infinitely stronger and left a long folded tube of fabric that allowed one nylon cord to be tied out to the corner poles that support the tent canopy.

I consider tie-out patches should be used in all good tent designs as they spread the load at places that experience considerable tension forces. They can be sewn on, but preferably, should be glued on (and possibly sewn as well), to better spread the load, and avoid stress concentration along the stitch line that takes most of the load.

Stitching through contact glue reinforcing tie-out tabs. The above tie-out patches were somewhat experimental so I thought it is was prudent to attach the tab with a line of double stitches. For this stitching, I used some very strong braided fishing line. “This was a fishing camp and such line is often carelessly left around as a hazard to wildlife, so the collected line found a positive use.”

The sewing was easy when the tabs were held firmly in place with glue. However, the fabric that had been folded and glued became very strong and quite resistant to penetration by the sewing needle. After breaking several needles, A thicker needle was glued into the end of a stick to make an awl. It could easily make pilot holes for the sewing needle. “This worked a treat!”

Additional tie-out tabs attached with contact glue and stitching. The next tent improvement was to put two extra tie-out tabs on the wall of the smaller tent (3*3M). These lessen the wind loading on the corner tie-out tabs. I placed these tabs on a horizontal tent wall seam that was formed just below each of the three netted tent windows. The fabric along this lay flat seam (three layers thick) made a very strong attachment area. These tabs were made and attached as for the above ones.

Load-sharing patches to prevent stitch stressing and leakage. These patches were applied to the parts of the tent roof that were held down to the supporting frame by wide and and adjustable Velcro loops. The tent roof had sewn reinforcing patches where the velcro attached to the canopy. As the hours went by, each wind gust would stretch the fabric along the top of the original patches and progressively more light would shine in through the growing holes.

Luckily I had a pre-cut ~30mm wide * 1500mm long strips of uncoated polyester to arrest this stressing of the tent fabric. With the velcro tension released, I first glued a strip of the fabric over the top stress line. Then I glued similar strips down each side.

This repair looks as though it has arrested the stress damage to the tent and it prevents water from entering the stretch marks. Importantly, the glue shares the load somewhat evenly over thousands of fabric threads on each side of the glue bond.

A water-shedding gutter. The pièce de résistance of the repair project was the provision of a rain gutter under the two tents where they adjoined each other along a 3M sides. I folded in half a 300mm wide rectangle of polyester fabric to make a rain gutter between the two tents.

The gutter had Velcro patches glued along the top of each side. The Velcro had matching patches that were glued to the inside of both tent eve lines. The latter Velcro patches were glued on so that they made the gutter have a good drainage slope to one side. As a finishing touch, I glued on a soft downpipe to transfer the water away from the tents and into a bucket. The downpipe was made as a glued tube of light polyester fabric and could feed the collected water into a bucket at a safe distance from the tents.

A substitute rain chute is shown below. With some effort the previous water tube could be removed without damage and the replacement chute was quickly glued in place between showers.

Discussion and conclusion

Some tinkering with contact glue and light polyester umbrella fabric enabled the repair of and improvement of two gazebo-type tents. These improvements that were done while camping, made them waterproof and much stronger to resist wind gusts.

This flexible contact glue can bond well to polyester tent fabric (presumed to be DWR-treated) and between this fabric and untreated polyester repair fabric (umbrella fabric) when other glues such as RTV silicone rubber and another mystery solvent glue will not bond well. Only time will tell if the glue maintains its bonding and flexibility, but I expect it will.

The success of the glue at bonding to DRW-treated polyester fabric is probably due to the toluene solvents’ (determined by me by chemists’ sniff) ability to dissolve, strip or disperse the DWR coating and allow the penetration of the glue into the base fabrics fibres.

Less powerful solvents such as ketones or ester (determined by me by sniffing) in the other mystery glue may not have such dispersing power.

This toluene-based flexible glue being a contact glue is very suitable to use for field repairs because it:

• It works on damp surfaces,
• Sets quickly to form good preliminary bond strength that increases over time,
• Needs only brief initial finger compression without the need for clamping and,
• The small (20ml) tubes of the glue will have a long life, in a field repair kit, if the metal seal under the screw cap lid is left unbroken and the solvent can’t escape.

The flexible contact glue will probably work with many fabrics other than silicone rubber-coated fabrics. However, using the other more benign glues where practical would be wise. The toluene-based flexible glue should be used as little as possible, preferably in the open air and away from flames for safety reasons.

This flexible contact glue has enabled me to make potentially great but crappy new tents serviceable in wind and rain as it should have been in the first place.

MORE ON ADVENTURE GEAR GLUEING

If you are a DIY adventure gear nerd like myself, you may be interested in my other glueing posts. However, before them, I thought a little ode about the fluid meaning of ‘nerdism’ would be fitting.

I tinkered in my shed like a passionate knurd,
Or should I use gnurd, a more gnarly word,
Or nurd, another old and similar pejorative,
Meaning of all, now have morphed into positive narrative,
So with obsession and a touch of pride I embrace the term nerd.

Silnylong glueing

Glued repair to adventure gear

RTV silicone rubber, Oogoo, Sugru, Kintsuglue and Tommy tap comparison

Glueing instead of pinning for sewing backpacking tents

DIY stove jack glue-on and sew-on for hot tents

Schnozzel bag repair

Tim

Addendum 1

One year later (Summer 2024) the tents were redeployed for another fishing season. They performed well through periods of rain and stormy winds and the glueing held up well with no leaks.

Seam taping. I applied external tapes to the entire ridge lines of the smaller tent. This was done with a thicker style of contact glue. In some places, the bonding was not as good as with the original thin contact glues. I think this may be because the thick glue does not penetrate into the fabric as well as the thin glue does.

Water pooling. The Ultimate Heavyduty tent described above has a further design feature (fault) that encourages water to pool at the bottom of each ridge line. Stretching of the bias-cut fabric along these ridge lines (without tensile taping) is the cause of this defect. I address this issue in all my lightweight tent designs by combining straight and bias cut fabric in every roof seam to restrict such stretching. Additionally, the two poles that support the roof peaks are spring loaded and they compress as the water loading increases. “A horrible consequence of the Heavyduty tent design is that as more water pools it increases the stretching and spring compression encourages more pooling until the water load becomes destructive. All the many other tents of this design in the camping area suffered the same pooling and pool noodles and broomsticks are used to reduce the problem.”

To address this problem I made some small aluminium battens (from aluminium fly screen frames) to form straight ribs under the tent corners to prevent pooling. Initially, they worked, but eventually, the Velcro attachment on one end of the batten detached (it was glued to the original defective seam tape.

Another solution to the pooling problem was to improve the fabric tension along the ridge. Luckily, I was able to use a portion of the above aluminium ribs to make a compression post that could stop the spring compression. These worked so well that we had no more pooling despite heavy rainfall. “I even had a spare post for our neighbour’s single pole tent of the same design.”