UKC

I bought a second hand tent recently and noticed that the material under the taped seams on the inside of the flysheet has a lot of rust-red patches. Is this tent mildew and are there any ways of ridding it?

In reply to bushwacka:
If it is under the tape then you'll have a lot of trouble getting rid of it. You could try soaking the whole lot in a bucket of mildew remover but you'll probably kill the proofing and may remove the tape.

In reply to bushwacka:
just dry it out thoroughly and it'll be fine. it's only really going to be a cosmetic thing.
If you really really want to get rid of it you could peal back the tape and replace it once you've cleaned it. you can get new tape from pointnorth.co.uk

In reply to bushwacka:

The tent is not necessarily irrevocably damaged. So long as the mildew is not too severe with signs of delamination between the the PU coating and the nylon fabric of the fly.

The key is to kill the existing mildew off so it doesn't spread. If left untreated, mildew spores will remain dormant on the flysheet and will become active once the tent is used again and condensation appears on the fly.

Don't use household mould inhibitors or bleach or try to machine wash the fly. Scrubbing the fabric with a mixture of equal parts lemon juice and salt seems to work for some people. I would recommend sponge wiping with dilute McNett Mirazyme. This was originally developed for deodourising wetsuits but does an excellent job of destroying mildew spores on tents too.

http://www.mcnett.com/MiraZyme-Enzyme-Based-Odor-Eliminator-P240.aspx

This won't rid the fly of mildew stains though - but this is only cosmetic.
Otherwise the tent should be perfectly fine after this treatment.

Remember to fully air dry your tent in future before storing it. Even the slightest damp from condensation left on the tent may be enough to invite another infestation. Hope this helps.