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The Polytops Story

SEAC has been manufacturing Polytops® pins and nails since 1981 and catered to the caravan industry when it first started. Over the last 34 years, there have been innovations and developments in the building industry that affect developments in the material used in Polytop nails. It is essential that those using Polytops® today understand the reasons behind what is being offered.

Polytops® were first used for fixing internal trims in static mobile homes and caravans. The pins and nails were then made of zinc plated mild steel with moulded plastic head in various colours. It was well suited for this internal application.

When the PVC fascia market began in the early 1980’s, common nails were used to attach fascia boards to roof rafters, and silicone was applied to mask the nail head.  This was a time consuming task besides leaving a poor finish.  A better solution was needed and the Polytop nail proved the ideal answer. Easy to fix and with a non-maintenance, colour
matching plastic moulded on the metal nail head, it provides a superior finish all round. However, within one to two years of supplying Polytops®, it was apparent that the zinc plated mild steel nail did not have the level of corrosion resistance required as rust stains and marks were appearing on the PVC Fascia boards. This was most prevalent in coastal and industrial city areas where the environment was most harsh.  Something had to be done.  In consultation with the major board manufacturers, SEAC then made the decision to upgrade the nail material to A2 (SUS304) Stainless Steel.  This is an austenitic stainless steel with improved corrosion resistance due mainly to the addition of Chrome (17.5% - 19.5%) and Nickel (8-10%).

Again, within a couple of years, problems began appearing with this material, with rust-like brown stains on fascia boards, again particularly notable in coastal regions.  SEAC swiftly remedied this by upgrading the steel again, this time to A4 (SUS316) Stainless Steel. This grade of steel has an increased nickel content (10-13%) and the addition of olybdenum (2%) further increases the corrosion resistance. It is commonly referred to as marine grade stainless
steel.  We introduced the A4 marine grade stainless steel Polytops® in around 1991 and have recommended only this grade for external use eversince. From that date we have had no staining or rust complaints.

We accept that the cost of A4 stainless steel Polytops® is a little higher than A2 or other coated products, but the corrosion resistance of Polytops® is far superior (as test result shows below).  Given that the cost of fixings on a PVC fascia installation is a very small part of the overall cost, why take the risk of remedial work to remove stains and other problems which will prove much more costly than the few extra Pounds to use A4 marine grade stainless steel quality
fixings. Remedial work could very well lead to entire replacement of boards, (the nails are not easy to remove), the use of scaffolding and towers, not to mention the cost of the labour time. Remember the old adages ‘Buy cheap but twice’ and ‘Penny wise, Pound foolish’.

We understand that in recent years, the economy has been tough since the financial crisis hit in 2008 inevitably leading to lower grade, lower cost material being offered in the market, and the temptation to save cost in this way can be compelling. However, we at SEAC decided very early on that we would not compromise on the quality of the fixings we offer.  So we only recommend and supply A4 stainless steel fixings for external fascia, barge board and trim fixing.  Considering we supply these products all over the UK and overseas, and cannot control where the product is used, we view this as the sensible thing to do, especially as the fascia board manufacturers offer 10-year or more warranty on their products.

However, that is not to say that we are dogmatic about the product. We constantly look to improve what we offer, and we regularly test both our products and our competitors’ products. The most recent was a salt spray test for corrosion performance done in 2014. The tests were carried out by an independent UKAS accredited laboratory, to British and European Standard. The images below speak for themselves.

The test was designed to simulate the product in actual use.  The nails tested were finished products taken out of an unopened random box of nails and hammered into wood, as it would be used in the ‘field’.  They were not ‘virgin’ nails, that is, before the plastic head was moulded. This is important as the process of moulding involves gripping the metal stem causing some wear and tear or for coated nails, the process inevitably damages any coating applied to the nail.  Therefore use of ‘virgin’ nails would give a misleading result.

As can be seen, the A4 nail shows no deterioration, unlike all other types of nail. This is why we only supply Polytops® in the A4 marine grade of stainless steel, and for all the professional manufacturers of PVC fascia profile, distributors and installers, we are sure you appreciate the value of quality and minimising your risk of product failure.

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