Roadster Fabric Top Detailing

[TOGWT]

Typical Fabric Top Composition:
Twill Fast™ II by Haartz, a three-ply composite comprising:
1.100% acrylic twill weave outer fabric
2.An electrometric twill weave inner fabric
3. A homogenously dyed polyester / cotton dobby weave lining fabric

b) Fabric tops:
Fabric convertible tops (mistakenly referred to as 'canvas') are considered to be the best. These are not vinyl or canvas, but a laminate consisting of several components, a top layer of a solution-dyed acrylic textile, a middle layer of butyl rubber or urethane, and the poly-cotton headliner.

A Fabric top comprises a multi-layer composite outer fabric, an inner layer and dyed polyester / cotton-lining fabric, the acrylic textile is very UV resistant...that's why it's used in this application. However, it has no inherent soil resistance; it is only water resistant, not waterproof. These breathable fabrics are made `water repellent' by a chemical treatment process during manufacture. It repels (beads) water, resists soiling and impedes mildew formation.

With time and use however the original treatment diminishes, making periodic cleaning and pre-treatment necessary, thereby extending the useful life of the fabric. After a year or so, fabric convertible topping starts to lose is soil and stain resistance, owners begin to notice the fabric gets wet and has to dry out when it rains.

The top doesn't leak because of the layer of butyl rubber (that's what it's for). However, wet fabric is an indication that the top can now soil or become stained and that it is time to treat the top with an appropriate fabric protector to prevent soiling and staining.

Road dust and dirt settles on the fabric weave, water and dirt act as an abrasive and if left will break down the fibres and abrade the stitching. There should be no need to wash your fabric top every time you wash your car. Each time you wash, even with the gentlest car wash concentrate: you are removing the previously applied protection. Just vacuum the top using a brush attachment to remove loose dirt and then rinse with plain water, blotting dry with a Microfiber waffle weave towel

There is a lot of misinformation about protecting convertible fabric tops; if your goal is maximum protection, do not use water beading/sheeting as an indicator, as its caused by surface tension; while its true that it is a visual indicator that a sealant previously applied is still present it does not guarantee that it’s actually providing protection. “If water beads on the surface it’s protected and able to repel stains” (Just like water beading on a paint; it’s due solely to surface tension) the answer to both is - No. The waterproof protection you get from a convertible top comes from the butyl rubber core sandwiched between the outer canvas and the inner pre-shrunk cotton layer. An applied protection only renders the fabric water resistant.

Rode & Schwalenbert Gmbn. (Germany) the world leading manufacturer of automobile convertible tops exclusively recommends Harrtz RaggTop Cleaners and Protectant. Developed specifically for cleaning, re-proofing and preserving convertible tops, these cleaning kits consist of two products:

1. Cleaner to remove soiling, stains and atmospheric pollution for both natural and synthetic materials. The best cleaners are formulated from low-pH (low alkalinity) and gentle enough for repeated use over years. They will rely on proteins and enzymes for their safe, but effective, cleaning power.

2. Fabric protector to re-proof and preserve fabric tops from the effects of water absorption, surface soiling and staining, and provide a sunscreen from UV radiation and subsequent fading. It has the best UV protection of any product on the market, and it repels dirt, grease, and oil. It doesn’t make your vinyl top glossy or greasy-looking. It will have the natural matte sheen of new vinyl.

Alternative product- this is the fabric protector recommended by Glen Raven Mills (Sunbrella) and the Haartz Corporation, 303™ High Tech Fabric Guard restores lost water repellence and stain repellence to factory new levels. It stops leaks, resists soiling and impedes mildew formation and helps protect against the sun's harmful UV rays.

Application Methodology
•Use a soft horsehair brush to remove any loose surface dust, use a lint lifter to remove lint from the fabric surface. Be careful around the rear window to avoid scratching
•Mask the areas around the fabric top with masking tape (3M® Painters Easy Release Blue Tape) also cover the rear window to avoid over-spray
•Shake product for 30-60 seconds to ensure even mixing
•With all cleaning products, always test a small, indiscrete area first to ensure it won't discolour or stain the surface, and ensure that the pH of the product is suitable for the material.
•Apply fabric cleaner (Harrtz RaggTop Cleaner) with a clean, damp applicator and leave to penetrate fabric for 10 – 20 minutes dependant upon stain. Gently scrub using a soft brush.
•Repeat if necessary; applying two light coats are better than the application of one heavy coat: allow drying thoroughly between coats.
•Rinse off using a low-pressure water hose and a soft horsehair brush
•Dry with a waffle weave Microfiber towel using a blotting motion to dry excess moisture.
•Allow the fabric to dry for as long as possible (preferably 24-hours) before using the protectant. An hour or two isn’t long enough, it may feel dry but that’s only the uppermost surface layer (using a protectant on a damp fabric will ‘seal in’ the moisture and encourage the formation of mildew)
•Apply a fabric protector (Harrtz RaggTop Protectant) on the dry fabric, keeping about 6-8 inches above surface and using a back and forth movements spray lightly but do not soak.
•Alternatively use a soft horsehair paintbrush and apply light thin coats, if time permits, two light coats are better than one medium coat, using gentle sweeping motion. Do not saturate. Allow to dry 10-15 minutes between coats, and to dry thoroughly before using or storing.
•Remove all masking tape and any other materials
•Be sure to remove any accidental over-spray from paint or glass surfaces immediately with a damp Microfiber towel or a 1:1 isopropyl alcohol / distilled water solution. On paint work use a pre-wax cleaner if necessary or fine detailing clay.
•After treatment the top will bead water, when the beading diminishes (usually at 6 monthly intervals, dependant upon climate / use) it's an indication that it's time for another treatment.

Maintenance-
Normal cleaning: Use a 10:1 solution of Woolite/ Distilled water and then apply 303 Space Protectant for UVR protection

For badly stained Amazing Roll-Off is a concentrated, water-activated cleaner. Wet the area to be cleaned with distilled water, lightly spray on Amazing Roll-Off and rinse thoroughly – We Are Car Care ! Car Wax - Car Polish - Auto Detailing Supplies & Car Accessories

For neglected convertible fabric tops leave above solution fabric cleaner on overnight, keep damp by covering with a plastic sheet, once stains are removed rinse thoroughly and apply protection.

Faded fabric - caused by ultra violet radiation (UVR) photo degradation or acidic attack; use Renovo Soft Top Reviver (Convertible top care by Renovo International - convertible top care specialists UK) a paint-on product that restores faded colour

Dust /Lint / Light dirt: Use a lint roller type brush (3M Lint Roller) to remove light dust and lint from fabric surface

© 2004 – 2007 all rights reserved - Jon Miller aka TOGWT™

[Dogged]

Great article. Now if I only had a roadster.