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Re: PMF and foam

PostPosted: Thu Feb 08, 2018 9:56 am
by John61CT
Excellent and thanks, will definitely include in pre testing

Re: PMF and foam

PostPosted: Thu Feb 08, 2018 11:32 am
by GPW
And just saying for those that love to pile on the Latex primer and then expect to sand it …. You really need to wait at the very least a couple weeks for the primer to harden completely to sand without gumming up your paper … much unlike our old car primer that can be sanded in a couple hours … So the secret is , the thinner you put it on the less you have to sand off and the quicker it cures … Smooth is more about how you put it on rather than how much you put on … :thumbsup:
You guys will have to Trust me on this … as a professional Artist , I’ve been priming canvasses for over 50 years now … tried every method … That’s why Foamies were so Natural for me … I had lotsa’ practice painting on canvas eh !!! :D

Re: PMF and foam

PostPosted: Fri Feb 09, 2018 3:35 pm
by badgerkeeb
I am finding that the key to a good finish is mostly in the primary application. The neater you apply the PMF the better. I haven't decided on what I'm going to use for the final coat yet. But I'm quite happy with the way PMF and paint is turning out :D so far. http://tnttt.com/posting.php?mode=reply&f=55&t=69931#

Re: PMF and foam

PostPosted: Mon Feb 19, 2018 10:18 pm
by CanuckShooter
GPW wrote:Take a hint from an old Artist … Try using GESSO to fill the weave … It’s not that expensive , it’s Very Thick , but workable and you can EASILY sand it to get a SMOOTH eggshell finish . We use a yellow plastic Bondo spreader to apply it … Since it’s also a primer , it saves a step … ( being Latex ( just like Gripper) , it’s paint compatable ) .
Applying it with the spreader prevents a huge build up or product , so not only does it fill the weave , it doesn’t affect anything else …. even repairs , should they be necessary …

Like this … ( what I use ) https://www.utrechtart.com/Blick-Profes ... 60.utrecht

Screen if you must for peace of mind , but it really isn’t “necessary" … I love the way everybody throws around the term “Puncture resistance” .. It reality it’s a “No-burger” … In all these years , nobody’s reported even a modest “puncture” , except me and that was through a RV “membrane roof “ of cheap vinyl , thin Plywood , foam and paper … Jayco roof … the limb went through it like it was butter … ( it was $5000.00 to fix the Jayco , a similar repair on a Foamie would be around $20.00 … DIY in 15 min. ;) )

There’s a Logic to all this …



Have you done this on any of your builds? Apply Gesso I mean.

Re: PMF and foam

PostPosted: Tue Feb 20, 2018 6:31 am
by GPW
CS, NO , we’ve used a primer , only bscause I don’t mind the look of the weave . But I’ve been priming Artist canvas smooth for over 50 years …. with Gesso :thumbsup:

You can buy a very small jar of ACRYLIC gesso at any art store and try it out ( testing , it’s what we do ) … If you like it , good , if you don’t . you’re not out a lot of bucks .…!!!

Re: PMF and foam

PostPosted: Tue Feb 20, 2018 8:25 am
by John61CT
What would you think of traditional Glidden Gripper + screening, built up until the fabric is thoroughly encapsulated

then just enough acrylic to give a smooth finish

then either a final couple topcoats of Gripper or some other puncture-resistant waterproofing paint or coating?

I'm not trusting gesso for the structural adhesion / tensile strength part, this way just need to trust self-adhesion compatibility

Does sticking to Acrylic give assurance of that?

Re: PMF and foam

PostPosted: Wed Feb 21, 2018 6:19 am
by GPW
If you don’t trust our word, experience , or the materials , then the only alternative is to TEST it for yourself .. :thumbsup:

Gesso and Gripper are remarkably similar chemically … both Acrylic . Gesso has more Pigment , threfore is Thicker …

Re: PMF and foam

PostPosted: Wed Feb 21, 2018 8:07 am
by John61CT
GPW wrote:If you don’t trust our word, experience , or the materials , then the only alternative is to TEST it for yourself ..

Gesso and Gripper are remarkably similar chemically … both Acrylic . Gesso has more Pigment , threfore is Thicker …
Sounds like the surface gesso should adhere to the Gripper just fine then.

Trust of forum members isn't the issue, I'm already pushing way past size / load boundaries for these techniques,

testing requires public liability, storm winds and highway speeds

so conservative over-engineering is only sensible.

Seems likely no one's actually used an only-gesso PMF at all yet right?

Re: PMF and foam

PostPosted: Wed Feb 21, 2018 1:23 pm
by GPW
The gesso should really be used Only to fill the weave ( it’s pricy) , which Is why we use a scraper to apply it , removing any extra to make it flush on the surface (smooth) … after that you can skip the primer and just paint it … the Gesso is also the primer ... :thumbsup: All depends what you want to do … Primer wouldn’t hurt over the gesso , but it’s just an extra step and expense.

Regarding size … You can always double up on the foam ,making a 4" or even 6” thick wall …. covered with a heavyweight (18-24oz. ) canvas with a thin paneling or chipboard inside should be INCREDIBLY Strong , yet light … Throw in a simple frame to hang it all on and you’ve got a solid vehicle … There is really no such thing as overbuilding with a Foamy ( unless you’re using WOOD !!! ) … Not at 2 lb/ cu.ft. ... :o Build it as Strong as YOU want to .. Make the build Foam thickness proportional to suit the size of the cabin ... ;) :thumbsup:

Re: PMF and foam

PostPosted: Wed Feb 21, 2018 5:00 pm
by John61CT
So that's in line with my thoughts, just using the gesso for the cosmetics on top, not as the tensile adhesive.

I will likely use aluminum posts for vertical heavy load bearing, roof rack up top, won't even try to get the foamie shell to support that.

Re: PMF and foam

PostPosted: Thu Feb 22, 2018 6:35 am
by GPW
Alumimum posts … that sounds like a good idea … We can’t recall anyone doing that as yet . :thinking:

Re: PMF and foam

PostPosted: Thu Feb 22, 2018 8:29 am
by John61CT