# Waterproofing



## craigfly06

I got a question for everybody, I see that everyone agrees that using Spar or marine varnish for paper mache. However, it is between $30-40 a gallon, which is alot. Plus I am sure it is an oil based product and need spirits to clean brushes and whatnots, just another mess to clean. Has anyone used a waterproofer like Thompsons or a deck sealer? Is the paper-mache not porus enough ? This was just a though abd wondering if anybody has tried and if it worked out? Is this not recommended because it is waterbased, if that is the reason I just answered my own question! LOL


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## RoxyBlue

I use a water-based sealant on mache pieces before painting them, then put on a final coat of water-based exterior varnish (the kind you find at Michaels). I've never used spar or marine varnish, but I also don't leave mache pieces outside for longer than the one day they are out for Halloween. And if it's raining, they aren't put out where they could get seriously wet.


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## goneferal

I sacrifice a brush and a mason jar with the spar urethane for my props. I use 3 coats before painting and leave them out in the rain for a few weeks. They hold up great, like they were made of plastic. Water based sealers will always fail. for mt creative energy and work. I use the oil based stuff. For $30 a can I can do at least 6 human sized props that are bombproof. I turn the brush, and sealed jar over to the monthly haz mat collection site for free.


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## fontgeek

You need to balance out the cost of your labor in making your creations against the cost of the better finish, and potentially the brush and container too. You can save your peanut butter jars for projects like this, the are cheaper (free) than a mason jar and you can put the lid on the jar to preserve the finish overnight between coats.
Working on a prop for a week and then balking at the extra few dollars to help it live for years seems awfully silly. If your prop gets ruined because of rain/moisture damage, how much are you out money wise and time wise? Can you get that money and time back?  If the answer to the last question is no, then you may need to rethink your line of reasoning for not using the better finish. 
You can save a chunk on brushes and finish if you line up several props to finish at the same time. You can keep using the same brush and you don't end up with all of the collateral loss in materials, solvents, dropcloths, etc. that you would finishing one project at a time.


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## dead hawk

i hear alot of people say sealents and even laquore but i think spray can clear no gloss paint is the best it saves you money and time you can spray a coat on wait for specified time spray another up to 4 then your done people even use that stuff for cars that sit out in the rain for years


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## fontgeek

Those spray on coats are so thin that any abrasion is going to remove them in a short amount of time. So the handling most props get will have those finishes ruined in a hurry, and if your prop is more than a lunchbox in size, you will go through a whole lot of cans of spray finish to get something close to a decent finish.


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## Aquayne

I have always wondered about using exterior latex paint as the paste? It may need watered down some, but I dought it.


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## discozombie

Im going to have agree with most of the above posts, if you spend hours/days working on a project the last thing you want is a pile of wet mush in your yard. All your hard work is gone... I know its expensive and Im on a tight budget as well but you will be sorry skimping on the last step. IMHO water based just dont hold up in inclement weather you can apply oil based with a cheep foam brush that you toss when you are done.


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## RoxyBlue

And one other thing - a sealant is only as good as the coverage. Leave any little spot unsealed, and water can get in.


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## VillaHaunter

I start placing my paper mache Jacks out the week before Labor Day. The Haunted Trolly Tour starts on Friday evening. Gotta be ready, they stay out until after Halloween. I use water proof wood glue in my paste and clay. 2 coats of the best exterior latex primer, followed by a base coat of exterior latex paint. Detailing done with latex or acrylic paint. A good spray with exterior clear flat enamel. I have a paper mache Bird Bath in the yard, yes the water bowl is PAPER, it has been out in the weather for 5 years and is starting to fail. Most likely due to the stray cat jumping onto it after the birds.


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## Lord Homicide

Has anyone tried concrete sealer?


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## Sawtooth Jack

Have not tried concrete sealer on mache.



craigfly06 said:


> I got a question for everybody, I see that everyone agrees that using Spar or marine varnish for paper mache. However, it is between $30-40 a gallon, which is alot. Plus I am sure it is an oil based product and need spirits to clean brushes and whatnots, just another mess to clean. Has anyone used a waterproofer like Thompsons or a deck sealer? Is the paper-mache not porus enough ? This was just a though abd wondering if anybody has tried and if it worked out? Is this not recommended because it is waterbased, if that is the reason I just answered my own question! LOL


You don't need to buy an entire gallon of Spar varnish. A quart of it will go a long way. I sealed my entire first mache project-which was pretty large-using a quart can of Spar varnish and barely used any of it, and I put a good amount of coverage on the prop. I imagine I'll be able to use the same can to coat all three of my ground breakers this year and still have half a can left over. Be warned though, Spar varnish will alter your paint colors slightly, as it has a yellowish cast to it.


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## bleigh

You can get spar varnish for 14 bucks at walmart. Its a quart but it goes a long way.


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## VillaHaunter

I used Spar Varnish on my first outdoor Paper Mache project, did dim the colors a little. But after a rain shower and frost over night it started to bubble up off of the acrylic paint. Latex primer 2 coats, latex exterior paint base coat and acrylic craft paint for detailing sprayed with clear satin enamel, has been working for me. I have my Jackos out in the weather for 2 months every year.


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## discozombie

on a side note to keep brushes soft for a few days wrap them in saran wrap. Ive had brushes wrapped for two weeks and they were still usable.


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## Allen H

Great thread guys! I will add that I have started using spray on Leak Seal by rustoleum and have been getting good results with it. Automotive undercoating or spray on bedliner work great also.


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## Pumpkin5

:jol:When using oil based paints I just wrap my brush in Saran wrap and then put it in a ziplock freezer bag and I store it in the freezer. Thaw it out and you are good to go!


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## Bethene

great thread, I have several prop heads made out of celluclay and paper clay, after I am done, before I paint it, used a water seal like you would spray tents with, then paint with regular acrylic paints, the coat several times with a matte clear spray,, The props are several years old, and are out maybe 3 weeks, and fall in Michigan is rainy alot of the time, this year we had massive down pours several times, and this is the very first time I had any problems, the nose of my favorite witch fell off, she needs a nose job now, but other wise, they have held up remarkably well,, I found at a surplus type store some spray cans of spar varnish, I will see how that works after I fix her nose


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## jackrum

This is a great thread. I have two props I need to figure out some waterproofing for. I had kind of assumed spray paint and latex paint would seal it but after reading all this I'm probably going to have to take it a step further. Here's hoping for a dry October.


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