Repairing tent's a degraded or sticky PU coating (guide)

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 Tigger 31 Jul 2021

Hi folks,

So, I recently purchased a second hand tent for £60 (F10 Nitro 200+). When I got home, I realised that the tents PU coating was sticky and degraded. Fortunately, the seller gave me a full refund and let me keep the tent!

So rather than throw it out, I thought why not try to repair the coating? (The new version of this tent is £400+)

This info took me a little while to put together as there are a lot of opinions on the matter of degraded PU coatings. But I thought it might be of use to someone someday so I've put together a little guide.

This guide should only be followed for PU coated tents, it won't work on Sinylon.

A bit of research threw up two options; 1) wash the tent with normal detergent to force the PU coating to delaminate 2) soak the tent in dilute ammonia to dissolve the coating.

I chose to experiment with the ammonia approach and then wash it for good measure.


1000ml Household ammonia 10% - I used ‘Max Strength’ from Homebase at 9.5 %

Gear Aid Tent Fabric Sealant x 2 bottles (only just enough)

Gear Aid Seam Grip + WP (polyurethane based adhesive) I had one of the extra large tubes to hand from another job (Mcnett brand £27 on eBay)

Toulene - approx. 150ml

Fabsil Gold

500ml – 1000ml Isopropyl alcohol

Talcum powder

Permatex flowable silicone (far more flexible than normal silicone and doesn’t require diluting with white spirit), ‘Seam Grip + Sil’ can also be used but costs more and maybe has a weaker bond.

Foam brush 4" or a thin foam pad

Coarse sponge

Stiff brush

Small paint brush (8mm – 10mm)

Large tub (enough for 13 liters + a tent)

Extra long rubber gloves

3M respirator mask

1) Peel off as much seam tape as you can and remove any guy lines.

2) Dilute 1000ml of household ammonia in 12 litres of warm water (wear a respirator if you value your lungs)

3) Submerge the tent completely agitate it and ensure all surfaces are covered, soak it for 10 – 15 mins, ‘stirring’ occasionally.

4) Ensure all PU coating is removed and scrub any remaining patches with a stiff bristled brush or coarse sponge

5) Rinse the tent in clean water.

6) Place the tent in a washing machine with normal detergent and wash without a spin at 30C (I added 3 extra rinse cycles) * This step can be skipped if your happy with the results of step 4.

7) Hang the tent up to dry.

8) At this point I used seam grip to repair any small holes in the tent - I used a small amount of Cotol 240 to speed up curing (2hrs)

9) This step requires a dry undercover area or a 24hr dry period. Erect the tent inside out and using a mixture or water, washing up liquid mixed 50:50 with isopropyl alcohol clean off any remaining PU coating or seam tape residue.

10) Hose down the tent to remove and liquid soap and leave to dry.

11) Once the tent is completely dry, shake your tube of Fabric Sealant and pour it into a container, using a foam brush or sponge apply an even layer to the whole tent (inner side of the outer that should currently be facing outward, if that makes sense?). This will take at least 24 hours to dry. After a couple of hours I used the remaining sealant to put a second coat on the areas that surround the inner tent.

12) This step requires rubber gloves and a respirator, Toulene is nasty stuff! Mix 3 parts Seam Grip with 1 part Toulene, this will make the seam grip easier to work with and improved curing times, only mix as much as you can use in 20 mins.

13) Cover all of the tent seams in this, as you would if seam sealing normally. Ensure that you also coat any areas of stitching i.e. guy points and peg points.

14) Once the seam grip is set apply a light dusting of Talcum powder to the whole tent to prevent surfaces sticking to one another.

15) Re-erect the tent normally and use a damp cloth to wipe down the outer.

16) Seal the outer seams with Permatex (I just smoothed it on with my finger ensuring to push it under any joins/folds near the seams). I used Permatex as my tent is a Silnylon/PU hybrid, meaning Seam Grip won’t bond to the outer as it has been treated with silicone on the exterior side. *Seam grip may work but I'd perform a small test patch first.  
*This step can be skipped if your happy with the interior seam sealing, it’s just my belt and braces approach

17) Using a wide paint brush apply Fabsil Gold to the whole outer, this will take approx. 6 hours to dry.

Now go test you work (your mileage may vary)

All the best

 Root1 31 Jul 2021
In reply to Tigger:

I'm impressed with your dedication, but honestly I couldn't be bothered with all that. I spent ages trying to revive an old tent, only to find the outer was covered in pinholes, so I ditched it in the end.

 Tigger 31 Jul 2021
In reply to Root1:

Tbh it was a labour of love, that and I really wanted a ligher two person tent for fair weather camping but couldn't fork out for something of a similar spec new.

 jimtitt 31 Jul 2021
In reply to Tigger:

Life is too short

 Tigger 31 Jul 2021
In reply to jimtitt:

Well it took less 3 days in the end, most of which was just waiting for stuff to dry. Not a bad little project for a rainy weekend.

 BrendanO 31 Jul 2021
In reply to Tigger:

Well-done for keeping it out of landfill!

 Tigger 31 Jul 2021
In reply to BrendanO:

Ah, well I'm not sure what's better for the planet, binning it, or using the numerous chemicals (and now empty bottles) to resurrect it!

 Tigger 01 Aug 2021
In reply to Tigger:

Well It rained on and off last night, inside reamianed completely dry and the new PU coating has dried to a nice matt with absolutely no sticky texture.

 deepsoup 01 Aug 2021
In reply to Tigger:

Like others, it sounds like more work than I'd have been willing to take on but I get how rewarding it must have been to achieve such a good result, well done.  I hope your new old tent has a good long second lifetime.

 Tigger 01 Aug 2021
In reply to deepsoup:

Lets hope so, for reference it was only about 5 - 6 hours of actual work (and about the same researching products). Just a lot of sitting around drinking tea/beer between coats.

 Tigger 01 Aug 2021
In reply to Tigger:

F***, I just noticed several glaringly obvious typos, including the title, sorry.

In reply to Tigger:

> Ah, well I'm not sure what's better for the planet, binning it, or using the numerous chemicals (and now empty bottles) to resurrect it!

Don't forget the poles and pegs, you've saved manufacture of those for a start, plus shipping of raw materials from the chemical plant to the fabric manufacturer, then from the fabric manufacturer to the tentmaker.  The tent and/or fabric manufacturer will have to go through similar amounts of proofing too.

 Philip 02 Aug 2021
In reply to Tigger:

How did you dispose of your ammonia solution and the waste water from cleaning the tent?

You know that the £400 tent can be bought for £249 online. 🤣

Shame they don't sell replacement fly sheets would probably have been the all round best option.

 Tigger 02 Aug 2021
In reply to Philip:

A "f10 xenon ul 2+" for £249, where do you find that??

As for the Household Ammonia, it's sold as a multi surface cleaning aid (sometimes a laundry additive as well I think). So it just got poured down the toilet.

Post edited at 17:44
 Tigger 02 Aug 2021
In reply to Philip:

Though to be fair I suppose the Ammonia wpuld have containes PU particles, Incouldnhave played that one better.

Anyway the repair cost £70 on a free tent, that I had initially paid £60 for (refunded). If it keeps going for only 5 more years I'd consider it money well spent.

 LastBoyScout 03 Aug 2021
In reply to Tigger:

Could have done with that about 18 months ago when I binned the fly of a Vango tent for exactly the same reason.

Tried to get a replacement, but to no avail - tent too old and no more stocks of them.

 Becky E 03 Aug 2021
In reply to Tigger:

Thanks for this. My small tent needs the groundsheet re-proofing, so this has saved me a ton of research.

 Tigger 03 Aug 2021
In reply to Becky E:

Just be careful with ground sheets, I've read that the PU doesn't always come off of them too easily for some reason (not an issue I've had). I have revived ground sheets with a double coat of Fabsil gold on the non PU side before, not a drop got through after 3 days of sitting in wet grass.

 Becky E 16 Aug 2021
In reply to Tigger:

Thanks - I might try that instead.

 maxsmith 16 Aug 2021
In reply to Tigger:

Good on you for keeping the tent out of word of caution: Permatex Flowable Silicone is nasty stuff and cancer causing so I hope you used thick gloves and applied outdoors.

 Tigger 16 Aug 2021
In reply to maxsmith:

Thanks for the tip, it was applied outside... And rubbed in with my finger (oops), though I'm struggling to find what exactly is its link to cancer, inhalation, skin or ingestion?

 maxsmith 17 Aug 2021
In reply to Tigger:

Okay sorry to have worried you! I don't know anything more I'm afraid just remember being suitably terrified when I applied it to a seam on my tarp..

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