Yeh absolutely, I’ve even sprayed it on top of single pack acrylics without issue.
You just want to make sure that you are giving a sufficient mechanical key, absolutely no finer than 320 grit. 180 grit is ideal, 240 and 320 will work, but any finer than that and I would be questioning the mechanical adhesion.
Cool man. Yeah I actually bought another gun since my first one was spitting real bad and since it’s a cheap pos I got the same one. Really am kind of hesitant to get a good gun with a 2.0 tip since it seems that polyester is harder to clean than regular automotive paint and primer. Maybe it’s just me…
But I had a real tough time with the stuff kicking early. It was hot and humid but things seemed to go alright until it started to kick in my gun. I was actually using my old pos gun. So I chalked it up to a whatever moment and opened up the new gun, cleaned it real fast and mixed up another batch of topcoat.
Well before it started to kick I actually dumped the little but left and poured some acetone in my gun to rinse it out. Dumped that and put some fresh acetone in and shook and sprayed some. I let it sit thinking it was clean. Mixed up some more topcoat.
I went to spray the first pass on some parts and it started to sputter and chucks of dried sunshield started to come out. I guess not a huge deal but now I need to wet sand a ton and wasn’t planning too.
The stuff kicked in my gun another 3-4 times, was a huge nightmare.
Any trips other than maybe using a slower mekp and also would a better gun be easier to keep clean then the cheap pos’s that cost $30 usd?
Guns aren’t going to make a difference. If you’re spraying in hot weather then you need to mix smaller batches and clean your gun properly between each batch. Not just spray acetone through it, but spray acetone and then pull it apart and clean it.
Makes sense. Strange that I’m still getting some surface pin holes. If you shoot me a pm with your email I can send you some pictures of what I’m talking about…
Yeah, guns suck, go spray can! Unless you need good UV protection, that is…
Anyway, anyone know how long to wait for sanding and polish after spraying with Spraymax 2k clear rattle can? It’s 100 degrees here this week and I’m going to leave it out in the sun tomorrow.
No idea about the spray can. I’ve never use the stuff honestly. But I’m
Sure there are instructions on the can…
On a side note when cleaning out my gun inbetween coats I didn’t spray upside down or holding the gun face down so I think some stuff started to harden at those angles missed. I recently did the same thing and everything was fine. Everything laid down nicely and minimum wet sanding is needed!
This is probably too late for you, but for others that may need this information;the SprayMax rattle can 2K clear can be wet sanded in 24 hours at 80F.
The longer you let it sit, the harder it becomes and the more sanding you will have to do to remove the orange peel. However, it takes a shine better if you let it sit for 48 hours or more before polishing. Of course, the time is reduced at higher temperatures.
I usually knock the surface down with 800, 1000, 1200, 1500 and 2000 used wet and then wait another 24 hrs to compound and polish.
The SprayMax is great stuff BTW, particularly if you intermittently use only small quantities, like I do. Yes, it is not cheap at ~$23 a can, but it is far cheaper than a $70 quart stuff that goes bad after using only 1/4 of it.
It takes some practice to get it to lay down nicely (light coat then 2 or more wet coats) and not run or form drapes and you will get some orange peel since you have no control over the pressure. It took me a couple of jobs to find the right distance, speed and flash time, but now that I understand how it behaves, I use it a lot and am please with the final finish.
S//
This is priceless information.
How long do you wait between coats?
Thanks in advance.
Meir.
Meir:
The instructions say to wait 5 to 10 minutes. I wait 15 or more, just to be sure, and have had no issues.
Like most clears, you don’t see it level and gloss immediately, so it is tempting to lay it down too thick and get runs. Multiple light passes, overlapping by 50% at about 6" works best on my small projects.
If you really like to use a gun, you could spray the contents of the can into the cup after breaking the ampule and mixing well, and then shoot it, but you would have to be fast as it tacks up rather quickly once exposed to the air. I have extended the 48 hr life of the mixed can up to two more days by storing it in a refrigerator.
I should also say that this stuff sticks like glue to a water-base color coat, so be sure that the base is thoroughly dry before clearing. I wait at least 24 hours and most of the time 48 hours. An adhesion promoter would not be a bad idea on difficult substrates.
As a hobbyist, I have gotten so much valuable information from this board that I am happy to be able to give something back.
S//
Well, seems like the spray can was a pipe dream for me also. Initially, it looked great, and I was excited to possibly find an alternative. There’s a few YouTube videos about using them, and I followed those, spraying nice thick coats, 10 minutes apart. A day later, they looked great. Nice and shiny and very scratch resistant with a little bit of orange peel. I let the pieces sit out in the 100’ sun for a week, and then went in to wet sand. On the first piece, I started with 1000 grit and decent pressure, not too much sanding, just for a minute. I dried if off and I had gone right through the clear coat.Ok, so I take the other pieces which I had cleared and added more thick(for a spray can) coats to those, coming out to a total of 5 or 6 total passes. Let those sit for another few days in the hot sun. From inspection it looks great, nice and shiny and not scratchable. This time I start with water and 1500 grit with very light pressure. Dry it off, and again, right through the clear coat.
Maybe I’m dumb, but it doesn’t seem like you can build this stuff thick enough like the Duratec to be able to sand it.
Duratec is a high build coating, so you’re getting 10-15 mils build in just 2 coats. Regular automotive coatings are generally between 2-4 mils.
That said, you should certainly be able to build the coating thick enough to sand. Not sure if you aren’t applying thick enough coats or you’re sanding too far, but something isn’t right there.
thanks again 
Yeah, a lot of things aren’t right with me. Nothing has made me feel quite as inept as this composites journey. I have a couple more spray cans, so I’ll use an entire one on a 12" x 16" piece and see what happens. If that works, it would still be worth it to me rather than getting out the compressor, gun, Duratec that you don’t know is still good or not, multiple batches and cleaning because of heat, etc. I really want the Spraymax to work out.
You know if the Duratec isn’t good any more, it gels. It appears much different to how it used to look when it was good, so it’s very very obvious when it’s off.
I definitely think for backyard hobby jobs, aerosol cans are the go. They perform well enough when you can afford to spend the time refinishing them, so it’s usually easier.
I hope this is in scope of the topic as it does relate to clearcoat, specifically, Duratec Sunshield Clear Topcoat- the type 904-061.
As I’ve heard works well, I intend to spray this in the mold (IMC) before layup (vacuum infusion using ProSet and Textreme carbon) to minimize or eliminate post processing.
Two questions.
1- Can the Duratec Sunshield Clear take a modest oven post cure of the laminate? Any increased temperature helps achieve physicals faster and can increase ultimates if elevated to 60 to 80 deg C. (140-180 deg F).
I don’t see a Heat Distortion Temperature recommendation for this product, the Duratec Sunshield, but it can take the sun! I will use appropriate ramp soak times.
2.- Maybe tricky, but I intend to mask off a portion of the IMC clear Duratec after a few hours and back it up with a color coat, so the finish of the part after demolding is a base coat/ clear coat.
Duratec products have good compatibility with most other products, including epoxies, in this case too, so I’m hopeful this will work well.
Does anyone have experience or opinion with this process?
I have a call in to Duratec but haven’t heard back.
Thank you,
Doug
The HDT is easy, it’s 120C. No issues at all with elevated temp cures, I’ve even used it on simple pre-preg parts.
The backing it up with a colour coat is slightly harder to predict, simply because there are so many different types of chemicals that it’s virtually impossible to say that your specific combination will work. I have done this myself with good results using a 2k polyurethane base coat behind the Duratec, so it can work. I’d recommend doing a small test with your specific materials, just to be sure.
Man duratec should give hanaldo some free gallons or make him a brand ambassador for the brand!
This an automotive product meant for touch ups so it probably is going on thinner than an IMC.
I am using the entire can on a single plug or hull of 1 meter overall length RC sailboat. (See photos to get an idea of the size.) Once you mix the can, you might as well shoot it all to avoid thin spots. Edges (at the transom on the boats) are particularly difficult to build up without runs on the sides. Sanding is done with a light touch, starting at 800 wet, backing the paper with a sponge. It is lots of sand, dry, look, and repeat.
IME the distance from the tip to the surface is critical in reducing the orange peel and I use more overlap than I do when using a trim gun. Lots of variables here and it is difficult to describe the technique. It took me several boats before getting what I consider to be good results.
S//
Thanks Hanaldo,
I couldn’t find the HDT anywhere. Check that box.
As you suggest, test panels are worthwhile. Although you may not use the Proset 114/210 that I am, what 2K basecoat did you use? That is a complicated, opinionated, project specific field of study in itself!
I would prefer not to use the iso chemistry, though. Hence more tests. I may try some rattle cans.
Thanks to all for this forum of knowledge.
I used Metalux Premium range, which is a reduced Iso polyurethane but still Iso based.