303 Fabric Guard and HOW to Protect a Convertible Top

[swanicyouth]

The Haartz company makes most cloth convertible topping material. They have made material for applications from the Mazda Miata to the Ferrari 360 - and many in between. If you think there is just one type of fabric material, you would be wrong. In fact, their website shows 20 types of material and the vehicles that use them.

The biggest surprise for me was finding out the applications are all over the place. You can't just say "BMW uses this, Toyota uses that"... In fact, it varies widely per model and even model year.

List of materials (from Haartz):



One of the main differences in the materials is how well they protect from road noise and "acoustics". In the aftermarket, different Haartz fabrics may be available for a single application - with different prices. So, if your ever replacing a top, besides getting the O.E. Haartz material, you may want to make sure you are getting a material that is equal to or exceeds the original material's acoustics. In reviewing their list, its not surprising most expensive cars use material with more acoustic protection (and likely more cost).

However, Haartz breaks all the materials down into square or twill weave:

Square:



Twill:



The top material (Haartz) is actually 3 layers. The layer that you are protecting is an acrylic or acrylic polyester mix. Below that is a "rubber combining film' (water proof) and below that is a cloth backing (lining):



Haartz recommends periodic cleaning and re-protection of their topping material with an aerosol protectant. I have a problem using aerosol convertible top protectants. The issue for me is, it's almost impossible to apply an even full coat of protectant (including the edges of the top) without getting overspray on the paint and glass. Let me show you what I mean.

I cover this part heavy with protectant because its a water channel to direct water off the drivers window onto the rear quarter panel





With an aerosol I can't get a good coat here:



Or here:



Or here:



Without getting overspray from the aerosol on the glass and paint and making a mess. So, I could tape the whole glass and paint off with newspaper. I've actually done that. However, it still seeps in and gets on the glass and paint for me. The aerosol protectant is wet, it easily seeps through paper.

What I think most people are doing is stopping their spray around here:



And leaving important areas less protected, as those areas will get some protectant, but not an even coat.

Now for narrow areas like here:



It's probably almost impossible to get a good even coat and not get some on paint or glass. I guess you could just wipe it off, but any fabric protectant isn't the easiest to get off of glass or paint. It bonds very quickly and just wants to smear, not to mention once its on your towel to any degree you can forget it. Alcohol or some other cleaner is required most of the time to get it off paint or glass 100%. I'm speaking from experience.

You could re-wash the car when done, but you can't get the fabric wet again until the protectant is 100% dry - and that would just be a huge waste of time. 303 says complete dry time is 6-12 hours in temperatures above 70 degrees. I'm not sure how long you would have to wait to re-wash with other products.

This is my whole issue with aerosols and fabric tops. Maybe my car has extra difficult spots, I'm not sure. But to me, an aerosol seems like the worse way for a detailer to apply a protectant to a convertible top.

A sprayer, like what 303 High Tech Fabric Guard Water Repellant (303 HT FGWR) uses, isn't the best way either in my experience. It's better, but far from ideal. It can also get overspray on other areas if your not super careful.

I've put a LOT of thought (and trial and error) into this, as I've owned a fabric top BMW convertible consecutively for the past 10 years. I think I've found the best way to apply a protectant that gets no overspray, needs no cover up, and needs no clean up - and applies an even full coat.

Use 303 HT FGWR & Ditch the Sprayer.

First, if your going to do this, your top needs to be clean and dry. Now they do sell special products to clean convertible fabric tops (303 makes one), but unless your top is filthy or stained, I've never found this necessary. I've found a good scrubbing with a car wash soap with no wax/gloss enhancers and a boars hair brush is usually all that is required.

Something like this:



If you need a little more power, you could use a Tampico brush and an APC that is safe on fabric like this:





Or even a microfiber cleaner like this:



Really anything that cleans fabric and rinses clean will do, since you will be re-protecting the material. Depending what you use, you may want to be careful around paint though. You could likely even use Woolite well diluted. Just rinse the top well to remove any cleaning product when finished and wait until the top is 100% dry before protecting.

My method how to apply protection is:

Pour a few ounces of 303 Fabric Guard in a small glass like this:



Then get a dedicated paintbrush like this:



Then PAINT it on. As your painting the fabric will turn white (color of 303). You will be like: "this is too much and is going to look like crap and jack up my top". Do not worry. Overnight, or less in the sun, the product will dry totally 100% clear. 303 recommends using the product in temperatures above 70 degrees F. I've found this doesn't matter, just that colder temperatures will increase drying time and you don't want to get the top wet or dirty until its dry. A heat gun may come in handy here.

When dry, it will make the fabric look rich and dark. Water will bead and roll off better than any LSP on paint ever did. There may be one or two high spots where some dried product is sitting on the fabric like dust. This, I believe, is where product was applied slightly too heavy, and a coat adhered to the fabric all it could. This is easily fixed by a quick brush of your hand or a towel. No problem. You will not have any streaks or brush marks.

This is one time where you almost can't use a product "too heavy". Paint it on like you are painting a wall, maybe a little less. Use enough to turn the area you are working on white. It will turn clear soon, that's OK. This will leave excellent protection on your top. Every inch will be well protected.

The protection will last quite a long time. This will protect the top from UV rays, which is the worst enemy of convertible tops. This is what causes the color to fade and black tops to look grey. 303 is also soil resistant and facilitates the release of dirt if the material gets dirty. It's literally a coating for your top. It does not discolor, in fact in my experience it adds to the color making it look new.

I've made a quick video to show you how 303 works. Keep in mind this is no new application. This application is AT LEAST 8 months old.

http://www.youtube.com/watch?v=8IeGrWdKId4

Thanks for looking!

[Jrocket]

Thank you!! Excellent review


This Review was something I was looking for and very helpful and Informative

[Wors]

Amazing review swanicyouth. Great tip on using the paintbrush with 303 solution. The overspray from aerosol protectants does require more cleanup.

[pcw25]

This is a great review! Nice job!

[Charleston]

I have recently installed a new convertible top which is twill, which is vinyl, not fabric.


Is the 303 Fabric Guard still the proper protectant to use in this case?

[swanicyouth]

I have recently installed a new convertible top which is twill, which is vinyl, not fabric.


Is the 303 Fabric Guard still the proper protectant to use in this case?

A little confused. The term "twill" is a type of weave, that usually refers to fabric IME. However, it could be vinyl with a twill like embossed pattern on the surface for aesthetics. I've seen that before, but I've never heard it called that.

Basically, if it's vinyl - this is the wrong product. You need to use something designed for vinyl. I know RaggTop has a specific product for vinyl tops, I can't recall if 303 has one off the top of my head.


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[parttimer]

I thought I saw someone use a roller for this as well? Would a foam roller be effective?

[SameGuy]

I just tape off and mask. Decent tape and split trash bags work well with the heavy spraying of 303. For other products that require lighter coats, old Xmas wrap and bed sheets work fine. Took me ten minutes to mask my small car, probably would be less if I had dedicated sheets or a 3M masker.

[swanicyouth]

I thought I saw someone use a roller for this as well? Would a foam roller be effective?

I've since switched from a paint brush to a small foam sponge. It works a bit better IMHO. No, you would never catch me using a bunch of tape and sheets and what not to cover up stuff when I can just apply it directly to the surface without incident.

Plus, I don't want these materials / textiles rubbing up against my black paint. Tape residue is another headache for me, for whatever reason - tape always leaves some glue on my paint. I'm always looking for ways to do stuff easier, with less work and clean up.


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[SameGuy]

Buy better tape. 3M Automotive Refinish, 233+ or Precision, or CarPro tape never leave residue and do not leak. And if I'm protecting the roof I haven't yet corrected my paint for the year. I see no need to worry about a flannel sheet damaging paint. I mean, have you ever seen how PDR guys go at your paint with hammers and stuff and the clear coat isn't damaged? If you're AR enough to take special care when detailing your car, you should be able to apply and remove masking paper or film (or a flannel sheet) without issue.