Canvas Roof Re-Proofing - Fabsil and Alternatives

[Boris113]

I purchased a new canvas for the 90 from another forum and whilst it's drastically better than the old ex-mod one, it doesn't seem to be more than shower proof. It's not a fancy Exmoor one (judging by backwards buckles etc I would hazard a guess at Britpart) but it was brand new when I received it and has only seen rain 10 times since fitting in the summer.

Once the canvas material becomes saturated water starts to build up on the inside of the roof eventually dripping everywhere and soaking the seats, seatbelts and me. Much like an old tent, it gets even worse if you touch the inside!

Has anyone used Fabsil or any other of the other re-proofing liquids with positive results? I used some years ago but it darkened the material and I would rather not do that to a new sand coloured hood.

Thanks in advance,

Harry

[Tanuki]

In the distant past I reproofed the entirely-inadequate `weather-protection' canvases on a semi-vintage tractor using "Thompson's water-seal" which is designed for use on masonry but did the job on canvas rather well too.

Given that I don't know what the original colour of the canvas was I can't tell if the slight darkening which resulted was a negative effect of the water-seal, or if it had just returned to its original colour.

[cackshifter]

I have no experience of it on vehicles, but Nikwax proofers work very well on clothes.

[timppl]

Many years ago I used Holts Dampseal ( I think it was ) to seal the hood on a Citroen Dyane. It worked very well as it applies a thin layer of plastic.

Tim

[Ally V8]

Thompsons water seal works a treat,but apply it with the canvas away from the car....

[101sean]

Thompsons water seal was good before it got environmentally friendly.

Fabsil or nikwax work but they are all a stopgap until you can afford a new canvas.

I get mine from Undercover Covers, wouldn't go anywhere else.

[tychoS]

I have had good succes with Fabsil on a Exmoor canvas softtop.

One tin is approx. enough for a 90" softtop. Applied with a cheap paintbrush

https://grangers.co.uk/product/fabsil-liquid

[disco2hse]

No.

What you need is one of those PVA based canvas sealing agents. Locally I use a product called Gourocks, like this stuff at this link. It is what is used for waterproofing horse covers so it is non-toxic and is very flexible.

You normally need to apply it once a year, depending on how much rain you get and whether your vehicle is garaged or left in the weather as mine is. Give it two coats each side for the first time and work it into the seams.

I have in the past driven through cyclones and not had a drop come through the canvas. The rest of the body, well that's a different story.

[Boris113]

Thanks for all of the advice, I have an old canvas so will try a bit of Thompsons and also Fabsil on that for a test and then decide. Had a look for the Gourocks but it only seems to be available in Aus/NZ which is a shame has it gets good reviews on the internet.

Unfortunately having just bought this canvas, I don't want to buy another one so re-proofing it is. The hood doesn't need to be 100% watertight given that it is stored indoors for most of the year but a little drier would be nice.

Many thanks

[=jon=]

Do you have any marquee makers / tent makers near you? Go visit them and ask them how they'd reseal an older canvas marquee - I'm sure they have some tricks they could share

[Superpants]

I used to use fabsil on the series 3 soft top with no issues- i takes best part of a full can to do though.

[A Twig]

We used to have a howling moon rooftent. Bought second hand after it had already had 2 years of fairly heavy use and sold on 6 or 7 years later. Every year it would get its "service", all canvas sprayed with fabsil and seam sealer worked into all the seams.

That survived some big old storms, force 6/7, trees coming down, torrential rain etc and we were completely dry with never a hit of a leak, so the fabsil and seam seal route gets my vote.