cleaning mold/mildew on canvas tent

[TNONMYMIND]

need help with big problem...
our 9x12 canvas tent has been in almost constant use since 2013...it is showing signs of
serious stains all over, black round spots which I suspect is mold/mildew...
we've been diligent with cleaning(sweeping) the dirt off from both inside and out and
packing it up only after it's dried out after a rain but the stains are getting more numerous.
does anyone know how to remedy the problem?


We put it up again just last week and it has been raining for the last 4 days. now we're finding puddles along the sides and seeing water lines on the ceiling even with a tarp over it.


things are not looking promising that we'll be able to continue to use it at this rate...
HELP, please...

[terasec]

Re: cleaning mold/mildew on canvas tent

mildew stains is not a big deal if stopped early before it degrades the canvas
chances are its mildew not mold but remedey is the same
dry it out,
spray mold/mildew killer remover, as per instructions,
let it dry, keep it dry,
will still have staining, but it will be just that stains,
if want to clean the stains, you do that afterwords, that will involve some bleaching(bleach/water mixture)
do not try to kill the mold/mildew and remove stain at the same time its basically 2 different treatments

[TNONMYMIND]

Re: cleaning mold/mildew on canvas tent

thanks terasec for the help...when I do this will I need to reapply waterproofing and how do I waterproof
the whole tent as it is soaking up water all over and leaving puddles inside the tent...

[terasec]

Re: cleaning mold/mildew on canvas tent

thanks terasec for the help...when I do this will I need to reapply waterproofing and how do I waterproof
the whole tent as it is soaking up water all over and leaving puddles inside the tent...

there are different methods to waterproof canvas tents, quick search online you will find multiple answers, depending on how traditional you want to keep it,
i dont want to give wrong info on that,
but to start heres one article on it

Commercial Products

I know of three classes of "waterproofing" compounds which have been used with varying rates of success. The first class consists of products which use silicone or a fluoride compound to increase the water repellence of the cloth. Basically an industrial strength "Scotch-Gard," they work by depositing a layer of moisture-repelling compound which prevents the moisture from getting a grip on the cloth, rather than by filling the pores in the fabric. Its downside is that it doesn't do as good a job of waterproofing as the other compounds and requires re-treatment about once a year.
There are several products of this sort. The most convenient,and most expensive, is a product called "Camp Dry" which is made by Kiwi (yes, the shoe polish people) and distributed through chains like Kmart. It comes in an aerosol can and covers, if memory serves, about 200-250 square feet per can. It has a distinct kerosene-like odor when applied, which mostly disappears with use. Since it doesn't saturate the threads of the fabric, it probably doesn't do much damage to the fire-retardant properties of the cloth or its ability to "breathe" (that is, allow water vapor to pass through the cloth).
Similar stuff, but water-based instead of solvent-based, can be had from:

• Nikwax Nikwax Waterproofing
• Iosso water repellent from Iosso
• Camp Kote from Camp Inn Products
• STARBRITE Waterproofing & Fabric Treatment with PTEF from West Marine

The latter also comes in larger bottles, which may be your most economical choice. You apply these with a brush, a squirt bottle or (my favorite technique) a garden sprayer. For lighter fabrics like the six-ounce stuff my sunshades are made of, this is the way to go, because it provides a fair amount of water repellence without adding a lot of weight. The second compound is Can Vac, available from Panther Primitives, some awning supply outfits and possibly other sporting goods stores. It comes in liquid form, which you either brush on or spray on with a spray rig. It does provide a good watertight seal for canvas, but has drawbacks of its own:

• It adds a bit of weight and stiffness to your tent
• As it dries (and possibly afterwards) it gives off fumes which you may or may not be sensitive to.
• It destroys whatever fire-retardant properties the cloth might have had
• If the cloth breathed before the treatment, it probably won't afterwards.

The third compound is Thompson's Water Seal, which people have sworn by, at, and off for some time now. It has all the properties listed above, plus the additional one of possibly harming your fabric. The people who make Water Seal say that it's supposed to be used to seal wood and masonry and such, and specifically exclude fabric from their list of applications, causing me to wonder if they know something that we don't. (If you doubt me, you can read it directly from the Thompson's web site. One of the reasons people have had varying results in their use of Water Seal may rest in the product's formulation. The story I've heard is that at some point, Thompson's reformulated their product for the California market to comply with that state's "clean air" requirements. The formulation did significantly reduce the amount of noxious gases released into the atmosphere, but also reduced the effectiveness of the compound as a fabric sealer. After a while, the story goes, they've started withdrawing the old formulation from other markets as well, so different people in different parts of the country are liable to get the new formulation instead of the old one.

Homemade Products

I'm including these mostly for historical interest. They were the products of a more innocent age, when people didn't know or care what they inhaled, or were ready to accept risks or inconveniences which we would rather decline. In a book entitled Let's Go Camping: A Guide to Outdoor Living by Harry Zarchy (Knopf, New York, 1951), I found this recipe:
"Dissolve a pound of laundry soap in two gallons of water. This can be done easily by first shaving the soap, then dropping it into the hot water and stirring it until it is completely dissolved. Soak the tent in this mixture until every fiber is completely saturated. Then squeeze out some of the surplus water, and hang it up to dry. If it's a large tent, you may spread it out in the sun.
"When it is thoroughly dry, prepare the second bath by dissolving a half pound of alum in two gallons of hot water. Immerse the tent in this solution and again saturate it thoroughly. It's best to leave it in this bath for a couple of hours. Then squeeze out the surplus and hang it up to dry again. Your tent is now ready for use."
I haven't tried this recipe myself, but it was printed in a real book with real ink, so maybe it works. Or, at least, it shows what people a half-century ago were willing to do to get a waterproof tent. I might add that this treatment probably leaves the canvas a bit more "breatheable" than solutions like Can Vac.
Another formula, found in G.B Colby and Bradford Angier's The Art and Science of Taking to the Woods (Stackpole Books, Harrisburg, Pa., 1970), is not for the faint of heart, or for those who worry about putting lots of hydrocarbons into the air (or their lungs). It says:
"If you'd like to treat a tent or tarpaulin with a good and proved homemade waterproofing solution, the job can be accomplished without too much difficulty. One of the best homemade solutions is simple to make and easy to apply. Just drop some blocks of canning paraffin into a gallon or two of white gasoline and let them stand for a few days or until as much paraffin as possible has been dissolved. The blocks may be eaten away entirely, or there may be nothing left but some thin, pock-marked paraffin wafers. About a pound of paraffin in a gallon of white gasoline is the right ratio, and you can shave the paraffin with a knife to speed up dissolving.
"Take this saturated solution out doors and -- keeping all cigarettes, sparks, or open flames well away -- paint it onto the tent or tarp. Use a clean, rather stiff brush, and work the liquid well into the material. particularly on roof, floor, and seams. The fluid will soak into the material and the gasoline will evaporate, leaving a coating of paraffin throughout the fibers. This treatment does not make the fabric too stiff, although it may stiffen slightly and shrink a bit as it dries. You can even use this solution on your convertible's top, and it will certainly make it waterproof. The white paraffin doesn't rub off much, and the color of the tent is not greatly changed, perhaps becoming a little darker.
"If you prefer to use some solvent other than gasoline, you can substitute either turpentine or benzene. But remember that these, too, are very flammable, so use extreme care.
"Probably the simplest of all home waterproofing methods is to rub block paraffin onto the material, section by section, as it's spread out on a smooth, hard surface. Once this is done, use a warm, not hot, iron to set the paraffin into the weave."
To this, I might add that you probably shouldn't use your mother's best ironing board.
I think this treatment was used on the tents we used in my Scouting days. As I recall, it had two drawbacks: it almost completely destroyed the breatheability of the canvas (not a problem for a shelter half, really), and when the material got really warm, like in the trunk of a car, the paraffin would tend to migrate, resulting in layers stuck together and generally uneven coverage.

[Mike]

Re: cleaning mold/mildew on canvas tent

My personal experience is that once a tent mildews, it is shot. That goes for both canvas and nylon. The cleaning solutions seem to somehow prevent post-cleaning waterproofing from working.

[JoeN]

Re: cleaning mold/mildew on canvas tent

I vaguely remember hearing about the soap and alum treatment for water proofing canvas but that was when I was a kid back in the 50s. I did't remember it was a two step treatment but I never saw it done either. Can you contact the manufacturer and ask if they have any recommendations about clean up and then water proofing? There are a few companies still around that make awnings and canvas products that might have some suggestions or have some products they would be happy to sell to you.

[Irate Mormon]

Re: cleaning mold/mildew on canvas tent

Most mildew treatments are simply bleach solutions. Not something I would spray on my tent walls (it will eat through them). If you can leave the tent in full sun for a few days that should kill the fungus.

[JeremyNicholson]

Re: cleaning mold/mildew on canvas tent

Not at all, mold remediation are not simple bleach solutions because only bleach can't remove the mold. You must go for other options to remove it permanently.

[JeremyNicholson]

Re: cleaning mold/mildew on canvas tent

Not at all, mold remediation are not simple bleach solutions because only bleach can't remove the mold. You must go for other options to remove it permanently.

[Mattryan]

Thanks

[downet]

I use Mr. Muslce the one woth mold sprayer and spray it all over but if everything like the whole tent is affected try using bleach that is safe for colored.

[janniesophia]

Re: cleaning mold/mildew on canvas tent


there are different methods to waterproof canvas tents, quick search online you will find multiple answers, depending on how traditional you want to keep it,
i dont want to give wrong info on that,
but to start heres one article on it

Commercial Products

I know of three classes of "waterproofing" compounds which have been used with varying rates of success. The first class consists of products which use silicone or a fluoride compound to increase the water repellence of the cloth. Basically an industrial strength "Scotch-Gard," they work by depositing a layer of moisture-repelling compound which prevents the moisture from getting a grip on the cloth, rather than by filling the pores in the fabric. Its downside is that it doesn't do as good a job of waterproofing as the other compounds and requires re-treatment about once a year.
There are several products of this sort. The most convenient,and most expensive, is a product called "Camp Dry" which is made by Kiwi (yes, the shoe polish people) and distributed through chains like Kmart. It comes in an aerosol can and covers, if memory serves, about 200-250 square feet per can. It has a distinct kerosene-like odor when applied, which mostly disappears with use. Since it doesn't saturate the threads of the fabric, it probably doesn't do much damage to the fire-retardant properties of the cloth or its ability to "breathe" (that is, allow water vapor to pass through the cloth).
Similar stuff, but water-based instead of solvent-based, can be had from:

• Nikwax Nikwax Waterproofing
• Iosso water repellent from Iosso
• Camp Kote from Camp Inn Products
• STARBRITE Waterproofing & Fabric Treatment with PTEF from West Marine

The latter also comes in larger bottles, which may be your most economical choice. You apply these with a brush, a squirt bottle or (my favorite technique) a garden sprayer. For lighter fabrics like the six-ounce stuff my sunshades are made of, this is the way to go, because it provides a fair amount of water repellence without adding a lot of weight. The second compound is Can Vac, available from Panther Primitives, some awning supply outfits and possibly other sporting goods stores. It comes in liquid form, which you either brush on or spray on with a spray rig. It does provide a good watertight seal for canvas, but has drawbacks of its own:

• It adds a bit of weight and stiffness to your tent
• As it dries (and possibly afterwards) it gives off fumes which you may or may not be sensitive to.
• It destroys whatever fire-retardant properties the cloth might have had
• If the cloth breathed before the treatment, it probably won't afterwards.

The third compound is Thompson's Water Seal, which people have sworn by, at, and off for some time now. It has all the properties listed above, plus the additional one of possibly harming your fabric. The people who make Water Seal say that it's supposed to be used to seal wood and masonry and such, and specifically exclude fabric from their list of applications, causing me to wonder if they know something that we don't. (If you doubt me, you can read it directly from the Thompson's web site. One of the reasons people have had varying results in their use of Water Seal may rest in the product's formulation. The story I've heard is that at some point, Thompson's reformulated their product for the California market to comply with that state's "clean air" requirements. The formulation did significantly reduce the amount of noxious gases released into the atmosphere, but also reduced the effectiveness of the compound as a fabric sealer. After a while, the story goes, they've started withdrawing the old formulation from other markets as well, so different people in different parts of the country are liable to get the new formulation instead of the old one.

Homemade Products

I'm including these mostly for historical interest. They were the products of a more innocent age, when people didn't know or care what they inhaled, or were ready to accept risks or inconveniences which we would rather decline. In a book entitled Let's Go Camping: A Guide to Outdoor Living by Harry Zarchy (Knopf, New York, 1951), I found this recipe:
"Dissolve a pound of laundry soap in two gallons of water. This can be done easily by first shaving the soap, then dropping it into the hot water and stirring it until it is completely dissolved. Soak the tent in this mixture until every fiber is completely saturated. Then squeeze out some of the surplus water, and hang it up to dry. If it's a large tent, you may spread it out in the sun.
"When it is thoroughly dry, prepare the second bath by dissolving a half pound of alum in two gallons of hot water. Immerse the tent in this solution and again saturate it thoroughly. It's best to leave it in this bath for a couple of hours. Then squeeze out the surplus and hang it up to dry again. Your tent is now ready for use."
I haven't tried this recipe myself, but it was printed in a real book with real ink, so maybe it works. Or, at least, it shows what people a half-century ago were willing to do to get a waterproof tent. I might add that this treatment probably leaves the canvas a bit more "breatheable" than solutions like Can Vac.
Another formula, found in G.B Colby and Bradford Angier's The Art and Science of Taking to the Woods (Stackpole Books, Harrisburg, Pa., 1970), is not for the faint of heart, or for those who worry about putting lots of hydrocarbons into the air (or their lungs). It says:
"If you'd like to treat a tent or tarpaulin with a good and proved homemade waterproofing solution, the job can be accomplished without too much difficulty. One of the best homemade solutions is simple to make and easy to apply. Just drop some blocks of canning paraffin into a gallon or two of white gasoline and let them stand for a few days or until as much paraffin as possible has been dissolved. The blocks may be eaten away entirely, or there may be nothing left but some thin, pock-marked paraffin wafers. About a pound of paraffin in a gallon of white gasoline is the right ratio, and you can shave the paraffin with a knife to speed up dissolving.
"Take this saturated solution out doors and -- keeping all cigarettes, sparks, or open flames well away -- paint it onto the tent or tarp. Use a clean, rather stiff brush, and work the liquid well into the material. particularly on roof, floor, and seams. The fluid will soak into the material and the gasoline will evaporate, leaving a coating of paraffin throughout the fibers. This treatment does not make the fabric too stiff, although it may stiffen slightly and shrink a bit as it dries. You can even use this solution on your convertible's top, and it will certainly make it waterproof. The white paraffin doesn't rub off much, and the color of the tent is not greatly changed, perhaps becoming a little darker.
"If you prefer to use some solvent other than gasoline, you can substitute either turpentine or benzene. But remember that these, too, are very flammable, so use extreme care.
"Probably the simplest of all home waterproofing methods is to rub block paraffin onto the material, section by section, as it's spread out on a smooth, hard surface. Once this is done, use a warm, not hot, iron to set the paraffin into the weave."
To this, I might add that you probably shouldn't use your mother's best ironing board.
I think this treatment was used on the tents we used in my Scouting days. As I recall, it had two drawbacks: it almost completely destroyed the breatheability of the canvas (not a problem for a shelter half, really), and when the material got really warm, like in the trunk of a car, the paraffin would tend to migrate, resulting in layers stuck together and generally uneven coverage.

Thanks for sharing such detailed information.

[zoey22]

For mold and mildew, chlorinated cleaners must be used. Use Blitz Mold Remover and X-14 Mold Stain Remover. (Blitz is a Shipp Chemical product that can be purchased at hardware and grocery stores). These calcium hypochlorite solutions are better at killing the roots or spores of mold and mildew. Always apply chlorine to a dry fabric. Use chlorine only when pop tops have mold stains. Chlorine will not whiten a puffy fabric, and prolonged use of bleach on vinyl fabrics will destroy plasticizers and stiffen the fabric. Chlorine cleaners can also dry rot polyester stitching at seams with the help of UV light.

[James Oliver]

It seems like your 9x12 canvas tent has developed mold and mildew stains, and you're dealing with water leakage issues. To address the mold, clean with a water-vinegar solution and ensure it's completely dry before storage. Check for damaged seams and use a seam sealer. Also, consider waterproofing the fabric and storing it in a dry, ventilated area. Regular maintenance and addressing wear and tear promptly can help extend its life.