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What to do with Your Aging Gore-Tex Shell

For 20 years, from 1979, we made a range of highly engineered Gore-Tex® shell wear.  Believe it or not we still get enquiries from past customers wanting to know about reviving their old WE rainshells. Here is the full extent of the advice we have offered in email replies to those individual enquiries.

Wash it, Before Doing Anything Else!

No matter what their age, Gore-Tex garments require regular cleaning, either by a regular domestic wash cycle or by dry cleaning. You can find the Gore-Tex outerwear care instructions on the Gore-Tex website: www.gore-tex.com . Go to Support, then Care Centre. If machine washing, be sure the rinse cycle does a thorough job. Rinse a second time if you are unsure. Outerwear that has been contaminated with oils, cosmetics or frequent contact with long hair is best cleaned by the dry cleaning process. As an example, our experience is that a single domestic wash cycle, irrespective of detergent type, has not been sufficient to remove all the oil contamination from long hair contact with a frequently used cycle cag. A prolonged test for waterproofness will show up a steady, general oozing leakage after five or ten minutes under the standard hydrostatic test pressure of 21kPa/3psi. This is a sign that contamination is still present in the membrane.

Whatever the state of your Gore-Tex or other shell it should always be absolutely clean and salt-free before making any repairs.

Delaminating Seam Tape

Very old garments, irrespective of their history of use (they may even appear to be in almost new condition) can suffer the problem of seam tape delamination. This results from the gradual degradation of the hot-melt adhesive on the face of the seam tape, the side that seals to the fabric in the application process. This thermo-plastic polymer is melted by a hot air stream then forced by rollers through the knitted backing layer to seal directly against the Gore-Tex membrane. It slowly loses its plasticity, either with age, contamination (especially around the hood and neck areas) or UV exposure. If your rainshell is suffering this problem, washing will certainly lift much more of the seam tape. This is unavoidable and the lifted tape would not have been effective as a seal anyway. The knitted backing on the seam tape and anything still attached to it can be simply trimmed off with scissors. If it doesn't come away with a gentle pull don't try to remove it.

There are two effective ways to re-waterproof seams from which the tape has delaminated. The best is by having a competent repair service completely remove the old tape and as much of the old adhesive as possible (with an industrial hot air 'gun') and then re-tape the seams. This requires specialised equipment - it can not be done with a hot iron at home. The second method is DIY using SeamGrip® PU sealant carefully applied and worked in along the inside of seams. SeamGrip is available from most specialist outdoor retailers. For product details go to www.mcnett.com .

Check for Fabric Waterproofness

All shell wear that has seen a fair amount of active service really should be assessed for fabric integrity before you take the decision to have a repair agency apply new seam tape. Re-taping is a significant re-investment in your garment and there is little point in making seams reliably waterproof if the fabric is damaged and leaking significantly. The membrane may have microscopic puncture holes from contact with thorny scrub or, though much less common, from worn-in grit or other misadventures. In writing this I am reminded of a fly fishing instructor who long ago returned his apparently new garment, complaining of leakage. It turned out to be full of fish hook pin holes, visible to the naked eye when the garment was held up against the light! Not all pins holes can be seen so easily.

There is a simple test you can do to check the membrane's condition for Gore-Tex garments made from3-Layer fabric. It also can be used on 2-layer fabric with a separate lining layer where it is possible to get directly to the inside surface of the fabric layer that carries the membrane). The ePTFE Gore-Tex membrane has a very thin smear of another polymer on the INSIDE surface. This thin film acts as a barrier to direct contamination of the ePTFE by body oils, particularly from contact with human hair. These contaminants destroy the surface tension of water on ePTFE, allowing water to ooze through the microscopic porous structure. This oleophobic ('oil-hating') layer also happens to be impervious to methanol and propanol. Iso-propyl alcohol (propanol) is recommended but methylated spirits also works OK. (Iso-propyl alcohol is available from some pharmacies and hardware stores). Take a laundry spray bottle containing either of these solvents and spray the inside knit lining of the (clean) 3-Layer lamination. If there is a microscopic puncture in the fabric and membrane originating from the outside of the garment it will certainly also have penetrated the polymer film. The alcohol will find its way through the perforation and soak into the microporous white ePTFE membrane, filling the voids and causing it to go transparent. This shows up as a dark spot, visible through the open knit of the lining fabric. (If you come across an extensive, well-defined dark patch that has no other explanation it is possible that this area is simply missing the thin smear of oleophobic polymer. Because this film is so thin these gaps are known to occur if only rarely).

When making this test pay particular attention to parts of the garment that are most likely to be exposed to damage: the outside of the arms, the lower front panels (and back for long, sit-on tails) and possibly under where your backpack shoulder and hip harness could rub in grit. Isolated punctures can be marked so they can be later sealed individually either with a disc of hot-pressed seam tape or dab of PU sealant. If there are extensive areas of membrane damage nothing practical can be done. The simplest solution is accept this fact and downgrade the rainshell for use as wind protection, to repel light rain (you will need to restore water-repellency for this - see below) or as a working garment around the garden. Do not rely on shells that have this level of damage for crucial rain protection is remote country.

Repair Services in Australia

There are two Gore approved commercial repair services in Australia. Contact them for seam sealing tape application and other repair work. (You may also contact us directly through our distributors, Sea To Summit. We will be happy to provide further advice if you require it).

Remote Equipment Repairs, Factory 40, 22-30 Wallace Ave Point Cook, Victoria 3030. Phone (03) 8360 7113 . www.remoterepairs.com.au / email: info@remoterepairs.com.au

Venus Repair Workshop, Suite 36, 104 Bathurst Street, Sydney, NSW, 2000. Phone (02) 9267 0706 .

Other Restoration Work

It is quite worthwhile maintaining the water-repellency of the outer fabric surface, particularly on garments that are not used off-track in dense scrub or worn under big backpacks with full harness systems. (In these cases the frequent brushing of foliage or 'scrubbing' from the pack harness quickly 'flattens' the fluoropolymer molecules that stand out off the fabric fibre surfaces to achieve the water repellency).  There are several advantages to a rainshell on which water beads and runs off the fabric, rather than wetting it out: The shell will remain lighter to wear, you will not suffer nearly so much cooling due to evaporation from a continuous film of water over the fabric surface and stains and external contaminants will have greater difficulty penetrating the fabric weave. Colder fabric (due to evaporation) will feel less comfortable against bare skin and more perspiration may condense inside the garment as a result of the somewhat lower temperature. Contrary to popular myth a continuous water film does NOT reduce the water vapour transmission rate of perspiration out through Gore-Tex fabric. The Gore-Tex membrane is effectively impermeable to air movement anyway but to understand why a water molecule (from perspiration) is not stopped by an external  film of water from escaping the inside of your rainshell , you will have to back out of this page and read the article on Staying Comfortable in the Outdoors... .

The most effective and therefore recommended restoration for Gore-Tex and other moisture-vapour-permeable (so called 'breathable') fabrics are made by Granger's of the UK. They include 30degC Proofer (wash-in and tumble dry) and XT Spray. Product details can be found at www.grangers.co.uk . Grangers also make combination, one-step cleaning and 'proofing' products.

 
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