Steve,
All three.
I’ve sprayed in cold temperatures, and the results sucked.
Ralph
Steve Featherkile said:Richard Smith said:
I use Behlen Dead Flat Spray. Although I haven't used it on something hot like a live steamer. If properly shaken it is absolutely "dead flat". So far I've used it over Krylon and Bondo products with no ill effects. It also literally welded decals down although I've only used it once for that purpose so far so it's hardly a scientific test.Dead Flat is available from Woodworker’s Supply and is shipped via UPS. About $7.95 per can with progressive discounts beginning with 4 cans. I’ve had no problem with the nozzles clogging either but I make sure the product is warmed before spraying.
Richard,When the directions on the can say “Use between 70 and 90 degrees F,” are they talking about the air temp, the temp of the spray can contents, or the temp of the target?
I think it must have something to do with humidity as well as temperature and also distance from the object being painted. I’ve sprayed with the temp in the 50’s and even high 40’s successfully here on the Oregon coast. In cool temps I hold the can in front of an electric heater and shake it periodically before spraying to equalize the paint temperature inside somewhat giving special attention to the nozzle area. I don’t know about excessive heat as it only rarely ever gets much above 75F here. When in doubt spray a piece of scrap first.
Besides Behlen’s flats and stains I use mostly Krylon paints and Bondo’s primers. Most others either go on thick or dry very slowly or both so I only use other brands if I need a specific color.
Matthew (OV) said:
A wise old fellow once told me the primary difference between the traditional Dullcote and the Krylon Matte overspray is that the former is NOT waterproof, while the latter is.... which, even if you're not running in a foul weather environment can make a difference, with things like humidity, and so forth. [b]I'll have to look at one of my cans to see if the Krylon is UV resist as well.[/b]And… yes, MIST. Not just the first coat. Get carried away, it’ll fog a milky white color. While some of this goes away as it dries, you can be left with a mess if you’re unlucky. Even then, there are potential corrections, but none are easy. So, mist, until you get the look you need.
My $ .02 … from my limited experience, and tendency to learn everything the hard way.
Matthew (OV)
Matthew, Krylon makes both kinds. The UV resistant is clearly marked on the can.
Art Sylvester said:My wife handed me a can of that just after the screw-up. Like Rustoleum it also contains Acetone, so it might be a little too hot for some subtle weathering like India Ink washes.
I've used Krylon matte for many years with good results, but last trip to Michael's turned up a new product: Americana acrylic Sealer/Finisher, DAS13 Matte. On the back side of the spray can it says it is "a clear, protective, non-yellowing, water-roof coating which provides permanent protection to all painted finishes. Colors are intensified with clear depth and given a matte appearance with a single application. May be used on wood, ceramics, plaster, papier-maché, and other craft products. Fast drying." I don't know that it is "best", but it worked fine on the deck girder bridge I built several weeks ago.
Terry -
I don’t doubt that the weathering job may effect resale value, but that doesn’t concern me. I never plan to sell this thing. If my kids can’t get kollector value when I’m gone, tough noogies 
Bring it down here and stick it in the yard…Shorty will wizz on it multiple times through out the day/every day and after several weeks of such it will have a very nice weathered patina.
I don’t know if any of the products mentioned above fall into this category , but photo matting spray is very good , I use it over dust camouflage and it does not affect the colour , depth or plastic . I also use it as a means of getting pencil lines to show up on shiny plastic .
Of course , photo shops are a bit thin on the ground now , but I have found it in art shops .
Mike
PS I do mean photo matte , not some equivalent you may be offered
Thanks Mike -
Nice to know there is a product that won’t eat the Dust color. That’s one of the first things I noticed went wrong. I had used Modelflex Dust in a few areas, one being the toolbox and I had a very nice looking mess on the lid. After spraying all of that subtlety was gone 
And we do still have a few good photo shops in the area.
After leaving the Shay sit for a few weeks, I was over the frustration and ready to try and salvage the job. At the local Walmart, there are only two choices for Krylon clear - Flat and Satin. I picked Flat and yesterday got the indoor spray booth set and did a test on the roof. I was happy with the result, so I masked off the moving parts and sprayed down the Shay with a couple of coats. I could not get the subtle weathering back, but overall I’m not unhappy with the result… [url=lsc.cvsry.com/Post/ShayWeather-1200-01.JPG]
(http://lsc.cvsry.com/Post/ShayWeather-800-01.JPG)
[/url][color=blue]FF: Click to Enlarge - IE: Right Click Photo and select Open Link in New Window to Enlarge[/color] The trucks were not clear coated - too many moving parts to worry about to use a spray. Same goes for the moving parts on the cylinders and drive line - they were masked off before spraying. [url=lsc.cvsry.com/Post/ShayWeather-1200-02.JPG]
(http://lsc.cvsry.com/Post/ShayWeather-800-02.JPG)
[/url][color=blue]FF: Click to Enlarge - IE: Right Click Photo and select Open Link in New Window to Enlarge[/color] The smoke box door was a particular challenge. My first attempt at mounting the #2 plate used a white metal number plate casting. Up in Canada, while running on Doug Matheson’s track, heat from the fire melted the casting. As it melted, some of the white metal deposited itself on the door. The resulting look was perfect, but didn’t cover the entire door. I tried heating the door along with some white metal, but even with flux, it would not coat the door. I tried solder and could get lumps, but not an even coat, so I gave up on that method. What I had left looked like crap, but I found that it took graphite from a pencil very nicely - so I spent an hour watching TV and rubbing the pencil led over every part of the surface I could reach. The left-over dust was used on a paper towel to coat the balance of the smoke box - over top of the clear. [url=lsc.cvsry.com/Post/ShayWeather-1200-03.JPG]
(http://lsc.cvsry.com/Post/ShayWeather-800-03.JPG)
[/url][color=blue]FF: Click to Enlarge - IE: Right Click Photo and select Open Link in New Window to Enlarge[/color] The hose on the front will be a hard suction line. It’s made from the covering of nylon rope soaked with Krylon Clear to stiffen it. I’ll fabricate some “fittings” and it will be done. [url=lsc.cvsry.com/Post/ShayWeather-1200-04.JPG]
(http://lsc.cvsry.com/Post/ShayWeather-800-04.JPG)
[/url][color=blue]FF: Click to Enlarge - IE: Right Click Photo and select Open Link in New Window to Enlarge[/color] The roof is wide masking tape, overlapped to make seams, then painted with acrylics and weathered with an India ink wash. I still need to add the crew, and a few more tools. The photos don’t do the colors justice - I’m planning on bringing this to York to display in the Alcove on Friday, and later at the Drag-N-Brag.
Looks sharp, Jon. Can’t wait to see it at York.
Sorry you struggled to get the results, but it looks great and I sure look forward to seeing it.
Great work Jon. Looking forward to it.
Thanks guys -
Before and After pictures in this Live Steam Thread
I wish I had taken in process photos. I thought of it, but never got the camera out.