Convertible (Roadster) Top Detailing

Porsche Cayman Roadster

Automobile manufacturers are receiving warranty claims from owners of convertibles that have disintegrated prematurely. Often this can be attributed to an unwitting detailing professional or vehicle owner who uses strong solvents or other harsh cleaners on a regular basis to keep the convertible material clean.

Unfortunately, such harsh cleanings tend to break down the material and the stitching that holds the various materials together. They also offer no protection from ultra violet radiation (UV-B) which will result in subsequent fading from photosynthesis

The Haartz Corp (acquired Rode & Schwalenbert that was established for 105 years) the world leading manufacturer of automobile convertible tops exclusively recommends Wolfsteins Pro-Series RaggTopp ™ Cleaner and RaggTopp ™ Protectant Developed specifically for cleaning, re-proofing and preserving convertible tops

Fabric tops

Haartz Corporation solution dyed acrylic topping fabrics - Cambria®, Stayfast®, Twillfast II®, Sonnenland®

Typical Fabric Top Composition: Twill Fast™ II by the Haartz Corporation, a three-ply composite comprising:

1.      100% acrylic twill weaves outer fabric

2.      Electrometric twill weave inner fabric and / or a layer of butyl rubber or urethane

3.      A homogenously dyed polyester / cotton dobby weave lining fabric

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

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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.

On fabric tops, it is recommended that you use a chemical with a fluorocarbon repelling system.   Such a chemical will bond with the fabric and repel liquid and dirt while at the same time providing ultraviolet protection.   Look for products that do not contain silicone, Freon, or chlorofluorocarbons (CFCs). 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

Although the fabric does not promote mildew growth by itself, mildew may develop on dirt and other foreign substances that are not removed. This is especially true in warm, humid, dark environments.

A regime to keep the fabric clean through regular washings, before it becomes too dirty, will enhance the life and beauty of the acrylic fabric and make successive cleaning easier.

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 it’s true that it is a visual indicator that the protection 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.

Most automatic car washes will not harm cloth top fabrics. Washes with water jets and hanging cloths provide a gentler cleaning action. Those using heavy barrel brushes could damage the top material. Haartz recommends hand washing. You don't have to wash your car's top every time you wash your car, but used occasionally it will remove ingrained soil /road dirt.

Every time you wash your convertible top, even with the gentlest car wash shampoo, you are stripping off any previously applied protection.  A better methodology would be to vacuum the top using a brush attachment to remove loose dirt and then just rinse the top with clean water.

Stitching (seams and rear windows)

The OEM uses a poly-cotton thread on the fabric tops seams, which is relatively weak, and requires ultra violet (UV) protection and a fabric protector to ensure its longevity. 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. 

DO NOT use uses strong solvents or other harsh cleaners on a regular basis as this will cause the stitching to fail. This is what holds your convertible top together so it’s very important to provide suitable protection.

The Haartz Corp (acquired Rode & Schwalenbert that was established for 105 years) the world leading manufacturer of automobile convertible tops exclusively recommends Wolfsteins Pro-Series RaggTopp ™ Cleaner and RaggTopp ™ Protectant   Developed specifically for cleaning, re-proofing and preserving convertible tops, fabric tops should be cleaned and retreated every three to six months, 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, 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.

These products are environmentally friendly, biodegradable and non-toxic

Alternative product

1. This is the fabric protector recommended by Glen Raven Mills (Sunbrella) and the Harrtz Corporation, 303 Fabric Convertible Top Cleaner and Protectant Kit - Fabric/Vinyl Top Cleaner is a proprietary blend of sequester agents, surfactants and hyper-wetting agents. It lifts and suspends oil and grease 303 High Tech Fabric Guard – is specifically developed as a UV screening protective treatment for aerospace and aviation applications, Regular use will provide the best protection against UV-B radiation High Tech Fabric Guard - leaves a like-new, non-oily, anti-static finish that does not attract dust. Treated surfaces actually repel dirt, oils, road grime, insect residues and tree sap. Restores lost water and stain repellency to OEM levels.

2.      Gtechniq i1 Fabric Nano Coating – coats individual fibres, which allows the material to breath, while at the same time repelling dirt and liquid. It has no affect on the tactile feel or colour of any fabric

Methodology

• Masking - use a 1-mil x 9-foot x 12-foot plastic drop cloth, cut it in two pieces (6 x 9-feet). With the convertible top up in front & back, drape one piece across the back as close to the top hinges as possible. Drape the second piece over the windshield and far enough 6-foot h back to cover the seat back, fold the convertible top down but do not latch. Mask the areas around the fabric top with masking tape (3M® Painters Easy Release Blue Tape)

• Mask the rear window - cover the rear window to avoid over-spray

• Use a soft horsehair brush to remove any loose surface dust, and then vacuum to ensure the surface is dust free, use a lint lifter to remove lint from the fabric surface. Be careful around the rear window to avoid scratching

Cleaning

Most off-the-shelf car wash soap/cleaners over time will damage the stitching on a fabric or vinyl top, it usually starts around the rear window.

• Shake product for 30-60 seconds to ensure even mixing

• All surfaces should be clean, dry and free of dust, wax or silicone.

• As 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 RaggTopp®) in a cross hatch pattern ////  \\\\ (to ensure an even coverage) with a clean, damp applicator and leave to penetrate fabric for 10 – 20 minutes’ dependent upon stain. Gently scrub using a soft brush to get into the texture of the fabric. Work the brush from the middle towards the outside.

• Repeat if necessary; applying two light coats are better than the application of one heavy coat: allow drying thoroughly between coats.

Rinsing

Rinse off using an open-ended low-pressure water hose and a soft horsehair brush Using a hose without a nozzle, this allows the gentle flow of water to rinse out the cleaner, gently brush the surface. Continue rinsing until the rinse water runs clear. Once the top is thoroughly rinsed, take a soft brush and “brush” the nap of the top in one direction.

Drying

• Dry with a waffle weave Micro fibre 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)

After washing with warm soapy water and drying the surface; use Plexus® Plastic Cleaner to clean and protect the surface. It will seal the tint material and keep it clean. It contains anti-static so it repels the dust and dirt normally attracted to plastic.

 It also leaves an invisible, micro-thin layer of protection, sealing the porous surface, making it more resistant to dirt, dust and other contaminants. Regular use will help prevent crazing, yellowing and oxidation which diminishes the plastic's lustre, and appearance, non-streaking, and it dries crystal clear.

Storage area

• Most roadsters will allow you to half-way open the top.  Clean the base where it seals against the paint, lubricate the hinges with lithium grease and then brush and vacuum the tops storage compartment.

Protecting

• Apply a fabric protector (Harrtz RaggTopp® Protectant or 303™ High Tech Fabric Guard) on the dry fabric, keeping about 6-8 inches above surface and in a cross hatch pattern ////  \\\\ (to ensure an even coverage) using a back and forth movements spray lightly but do not soak (if you use too much product it will turn white, rinse away excess and allow to dry) Two thin coats are better than one heavy one

•Once you apply the first coat rub the protectant in while it is still damp, this will help both durability and help the second coat adherence

• Always ensure that the stitched seams have adequate protection applied to them

• 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, rub the protectant in while it is still damp. Do not saturate. Allow to dry 10-15 minutes between coats, and to dry thoroughly before using or storing.

Lint Removal

Once the top is completely dry, remove any lint or brush fibres with a lint roller or the sticky side of plastic packing tape. Any lint left on the top will ruin the appearance of your fabric top.

• 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, dependent upon climate / use) it's an indication that it's time for another treatment.

Maintenance

• Providing the fabric is not soiled by any foreign matter that needs to be addressed (i.e. tree resin (sap) bird or insect excrement, etc ) routine cleaning should comprise of  vacuuming  with a soft bristled attachment and then use a lint cleaning roller to remove dust (including pollen) There is no need to rinse the top with water or use a car wash concentrate or a soft top cleaner; this will only weaken the protection provided by the protectant and is not a necessary part of a maintenance regimen
• Apply ultra violet (UV-B) protection; periodically to avoid photo degradation(fading), dependant on climatic conditions as its protection degrades over time, apply protection (303™ Aerospace Protectant) to fabric by keeping spray about 6-8 inches above surface and using a back and forth movement spray lightly but do not soak fabric.
• Apply a fabric protector (Harrtz RaggTopp® Protectant) each quarter (adjust for use / and or environmental conditions)

Harrtz RaggTopp® Horse Hair Brush - this natural horse hair brush will not harm the finish of your convertible. It’ nonabrasive and is incredibly soft, yet strong enough to get into the fibres and texture of your fabric of vinyl top. The design of the brush makes it easy to grip and gently scrub dirt and grime from your convertible top, car cover or other fabric and vinyl material like tonneau covers, vinyl awnings.

Renovo Soft Top Reviver

Available in Black, Dark Blue, Green and Brown to match your convertible top’s hood; that will make your convertible top look like new again, great for classic and modern convertible tops

·         Ensure that the soft top is thoroughly cleaned (Renovo Soft Top Canvas Cleaner)

·         Ensure that you have sufficient Reviver to complete a full coat.

·         Shake the bottle prior to use

·         Be diligent in removing previous waterproof coatings prior to application of Reviver.

·         Keep a soft damp cloth ready to wipe off any splashes or dribbles on paintwork and glass.

·         Work in a timely fashion to ensure that the edges of the freshly applied Reviver do not dry out too quickly.

·         Work from the centre outwards round and round the vehicle.

·         Only apply to a dry top

·         Allow Reviver to dry completely before applying further product or taking out in the rain.

Do not - apply the Reviver in direct sunlight or on a hot day that will cause it to dry too quickly, allow to dry on glass and paintwork, apply to a soft top that has been coated with a waterproofing agent without removing the proofer first, apply to vinyl soft tops - http://www.renovointernational.com/

Specific Stains

Mould / Mildew - dirt and moisture are essential to mould / mildew propagation; if the contamination is not removed the fungus will degrade the material. Just like mould and mildew contamination in other areas, you cannot wash or shampoo it away; this only exacerbates the problem.

The fungus is caused by living organisms that must be killed before the material is cleaned, and all the moisture is eliminated by thoroughly drying the material or the mildew will return

a) Use a medium soft brush and a 4:1 solution distilled water / ammonia and then rinse with cool clean water

b) For tougher stains apply a solution of no more than 1/2 cup (4 oz.) bleach and 1/4 cup (2 oz.) Raggtopp™ Cleaner per gallon of water and then rinse. Mould / mildew may require repeated cleaning

Please note that excessive soaking with bleach solution can weaken seam threads. Rinse the entire top to remove all of the bleach solution from the vinyl, and rinse the car body to prevent streaking on painted, chrome or other surfaces.

Badly stained material - wet the area to be cleaned with distilled water plus (a) or (b) above, lightly spray and rinse thoroughly. 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. 

Renovo Soft Top Canvas Cleaner - Dampen the hood, apply the cleaner with a paint brush, and allow dwelling for 20-30 minutes, and then agitating it with a stiff brush and warm water, before rinsing.

Bird Excrement - this product will remove it without damage to both vinyl and cloth it will not harm its water repellence. Poop-Off Bird Poop Remover is a non-toxic, biodegradable, active enzyme formula that removes droppings and residues composed of all types of avian diets including, seeds, fruit, nuts, meat, vegetables, nectar, bugs and grains. Originally a marine product, it will not harm the tops water repellence

Tree Resin (Sap) – place a 1:10 solution of Isopropyl alcohol on the resin and allow to dwell and then scrape with a plastic razor blade. Thoroughly rinse surface with clean water and then replace protection

Paint Overspray -

•         Use Mineral Spirits (a safe solvent) lightly rub the over spray until removed

•         Rinse off using a low-pressure water hose and a soft horsehair brush

•         Dry with a waffle weave Micro fibre 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 RaggTopp® Protectant or 303™ High Tech Fabric Guard) on the dry fabric, keeping about 6-8 inches above surface and in a cross hatch pattern ////  \\\\ (to ensure an even coverage) using a back and forth movements spray lightly but do not soak (if you use too much product it will turn white, rinse away excess and allow to dry)

•         Always ensure that the stitched seams have adequate protection applied to them

•         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.

Faded fabric - caused by ultra violet radiation (UV-B) photo degradation or acidic attack; to help to keep or revive the colour - Renovo Soft Top Reviver a paint-on product that restores faded colour - www.renovointernational.com/faq.html 

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

Renovo Fabric Hood Ultra proofer –gently lifts dirt, road grime, bird dropping, tree sap and salt from your canvas top without compromising water repellence. A brush- on protection specifically formulated for all fabric convertible tops, and boat covers.

Protects the material from the elements, sun damage, fading, stains and waterproofs all in one operation Contains a strong UV Inhibitor and is mould and mildew resistant that will help to prevent the harmful penetration of everyday dirt into the fibres of new and old convertible top material.

To help to keep or revive the colour - Soft-Top Reviver www.renovointernational.com/faq.html

Convertible Top Mechanical Maintenance Care - use a Q-tip and some lithium grease to lubricate the various parts under the mechanism for the convertible top, now if you look on this type of top there's all kinds of

Rear Window

Most off-the-shelf car wash soap/cleaners over time will damage the stitching on a fabric or vinyl top. It usually starts around the rear window

Clean surfaces using Iz einszett 'Plastik-Reiniger' an intensive, non-corrosive, non-acidic two-phase deep cleaner for urethane that removes grime build-up thoroughly and effortlessly, these chemicals restore the original texture, tactile feel and resiliency and optical clarity; use to clean all coloured and clear water-based acrylic and vinyl; this product is biodegradable and formalin-free

Renovo Clear Plastic and Window Polish - a one step cleaner and polish that will remove or reduce clouding, fine scratches and help restore the transparency to all clear plastic. Shake the bottle well and apply a very small amount to a soft, 100% cotton towel, work into the surface with moderate pressure, until all that remains are a faint haze. Burnish to a shine with a clean, 100% cotton towel. Some areas may require 2-3 applications.

Plastic polish will not remove clarity defects that are within the plastic or deep scratches (1.0 µ) but it will remove external/surface scratching and oxidation (yellowing). Prior to application of a plastic polish ensure that the surface is clean and free from dust particles by washing with a soft cloth and warm water. Be cognizant that heat may cause the plastics to deform. Using an abrasive polish may remove the UV protective coating

After washing and drying the surface; use a plastic polish that is safe for all types of clear and coloured (polycarbonate) type plastics i.e.  Lexan®, Perspex, Lucite and most clear acrylics - Novus 1 or 2  

The type of polishing cloth you use will make a difference; nonabrasive, absorbent and lint free. Uses a soft 100% cotton towel (Swisswax or Zymol) avoid using polyester (Microfiber), which can scratch unprotected plastics.

If using a machine polisher (Novas 2 & 3) use low speed and light pressure with a clean 100% cotton bonnet (as opposed to foam) to avoid overheating the plastic

Novus 1 - gently cleans all plastics without scratching, leaves a lustrous shine that resists fogging, repels dust, and eliminates static.

Novus 2 - removes fine scratches, haziness, and abrasions from most plastics (exceptional for removing scratches from Plexiglas). Use repeatedly and restore faded and discolored plastics.

Current Information

To be of real practical use, a subject like automotive detailing requires a great deal of research, and updating as new products become available. The advent of materials like detailing clay, micro fibre technologies and finely milled micro diminishing abrasives, suitable for ceramic nanotechnology paints are examples of why it’s so important to monitor the industries new products, chemical technologies and ideas that are constantly being introduced, as are the techniques for applying them, hence all of the in-depth articles will be up-dated and revised on a regular basis

Always be willing to learn; because the more you learn, the more you’ll realize what you don’t know. You should never stop learning, and your quest for information should be part of your everyday process. It is said that knowledge is power, with the caveat that it includes access to a reliable information sources. I would like to think that these articles become an asset to anyone who is new to detailing and to professional’s alike, as well as industry experts who seek to advance their knowledge.

I hope these articles are informative. They are based on the current status of technical development as well as my experience with the products.By having some understanding of the ‘What’ and ‘Why’ as well as the ‘How’ along with a little science to help you understand how the chemicals we use react, you can achieve the results you desire.

I would appreciate it if you would share these articles as it helps other detailers further their knowledge.

As always if you have questions, I’ll do my best to answer; bear in mind the only stupid questions is the one that was unasked. Questions and/ or constructive comments are always appreciated

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