# Ben Moore penetrating oil primer



## Likeason (Jun 28, 2010)

Three days ago I pumped Ben Moore alkyd slow dry penetrating oil primer on the exterior of my house. Why not four hour dry? The four hour dry can does not claim penetrating adhering or bonding. Anyway that was the debate at the dealer where I bought 35 gallons to pump. 

Since it is not yet dry and the humid wether is coming I was just curios about when the finish coat can be applied. I am assuming it may be best but not necessary for it to be completely cured. With no rush on finishing I was wondering how long this stuff can possibly stop moving around to the touch. 

My best guess is it will be ready by the time all of the spiders have set up there webs again


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## chris n (Oct 14, 2003)

pumped? :blink:


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## Likeason (Jun 28, 2010)

Airless sprayer


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## MAULEMALL (May 16, 2010)

BENJAMIN MOORE® 
FRESH START® MOORWHITE® 
PENETRATING ALKYD PRIMER 100 


• For best results, top coat 
should be applied within a 
reasonable length of time — 
preferably no more than one 
month after priming 

Technical Assistance 
Available through your local authorized independent Benjamin Moore & Co. 
retailer. For the location of the retailer nearest you, call 1-800-826-2623, see 
www.benjaminmoore.com, or consult your local Yellow Pages. 



Technical Data. 

White

Vehicle Type 
Alkyd
Pigment Type 

Titanium Dioxide
Volume Solids 

66%
Theoretical Coverage At 
Recommended Film 
Thickness 
500 – 550 Sq. Ft.
Film Thickness 
— Wet 
— Dry 
3.1 mils2.1 mils
Dry Time @ 77° F 
(25° C) @ 50% RH 
— Set to Touch— To Handle 
— To Recoat 
— To Service 
6 Hours6 Hours
Overnight 
Overnight

Dries By 
Evaporation, Oxidation
Viscosity


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## MAULEMALL (May 16, 2010)

I obviously edited the page from this page... 
http://www.benjaminmoore.com/bmpswe...0&_pageLabel=fc_footer_hiddenPage#description


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## Gough (May 1, 2010)

I understand why you used that primer; we've been using it (or similar long-oil primers) on exterior wood for years with good results. The BM primer is normally good to go after drying overnight, but we make it a point to apply a thin coat, worked well into the substrate. Based on the slow drying that you're seeing, I have a couple of questions. What sort of application rate did you use? From the slow dry time, it sounds as if you may have applied a pretty thick coat. Did you really use 35 gallons of primer? I ask that because, at the recommended spread rate, that would be at least 17,500 square feet. Even allowing for spray loss, that's a honkin' big house. Did you back-brush the sprayed primer? Our experience has been that it takes a big crew to back-brush behind an airless in a timely fashion. Otherwise, you're back-brushing primer or paint that's been on the wall for awhile and has already started to dry. What was the moisture content of the walls when you applied the primer? We see some guys around here priming within a day or two after they've power-washed a house, which may be pushing it, even on our driest days.

If you do have a thicker than recommended film thickness, it's probably better to let it dry for a few more days. As rule of thumb that we use is to cover ooil-based primer within a week to minimize saponification.


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## Gough (May 1, 2010)

I just re-read the original post and saw the part about "moving around to the touch"! That definetely sounds like a thick build for an oil primer. I can't come up with a citation, but it was probably one of the paint rags (trade magazines) that talked about the difference in alkyd versus acrylic primers. The upshot of it all was that oil primers should be applied in a very thin film to maximixe penetration and retain flexibility, while acrylics perform better with a substantially thicker build.


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## Likeason (Jun 28, 2010)

Hi All thanks for your support. 
Yes I was power washing a week earlier Yes I have a heavy coat over a lighter coat. The soffits are the heaviest and are firmer every day. This house
has large sections of concrete blocks poured in the shape of oversized brick. The brick has heavy latex that did not power wash off. I was spraying to fill the mortar angles then covered as thin of a coat as possible with an 8 inch fan tip. that single coat is still moving around some. I recoated all of the window glaze and unexposed wood and anything not filled by the spray with a brush after spray day. the house is 3500 square feet with 5 foot overhangs 2.5 levels. It is a monster to me since I am alone on it. Prep still took two weeks including changing all rotten sections. The heat started today.


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## Gough (May 1, 2010)

My back-of-the-envelope calculations come up with something on the order of 7000 ft^2, so it sounds like you may have put on a pretty thick coat. Something that size would normally take abuot 15 gallons of primer at the recommended coverage. If you're using an 8-inch fan tip, that may explain some of it. In my experience, that's an awfully dense pattern for oil primer/paint. I'm also surprised that you went with an oil primer for CMUs. Unless otherwise specified, most oil primers are not particularly alkali resistant, but latexes are very good in that regard.

Your profile doesn't mention where you are, but I'd be concerned if you're in an areas with wide seasonal temperature variations. It's my experience that thick layers of oil-based primer are brittle enough that they'll fail prematurely when subjected to wide swings in temperature.


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## Likeason (Jun 28, 2010)

Thank you guys so much. I thought I would get good advise from the dealer. This site makes more sense. It is thick and still drying good thing I have a month to apply the finish 
I will come back and let everyone know how soon pre mature failure takes.


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## tersh (Jul 19, 2004)

*oil primer failure?*

I'm interested in what happened it's been about 5 years?


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