I’m using the Duratec 1045 Sunshied. I’m using in in a post mold application. My room temperature is about 78F. My parts have been sanded down and alcohol cleaned part surface. I’m using a cheap harbor freight spray gun (maybe an issue?). I’m mixing about a 40gram part A with 2% MEKP. My parts are coming out very textured and hazy looking. I haven’t wet sanded and buffed the finish yet, however I’m not used to top coats coming out hazy and textured even prior to a wet sand and polish. Can anyone offer me advice or chime in their 2 cents? Thank you for the help community.
I don’t use sunshield but when I use other Duratec finishes I thin them with MEK available at most hardware stores and it sprays nice and smooth with a Harbor freight gun.
Suggest you find a local auto paint shop and bring over a case of good beer, your parts, your product, and your equipment and have them show you how it’s done. Best case of beer you’ll spend.
What size tip. I use a 1.8 but have used 2.0 tips. I also use a cheap pos gun. I get good finishes but still need post work. It looks as if you are not loading it on thick enough or maybe air pressure is to low or high. It’s hard to say.
You haven’t done a thick enough coat, and the coating wasn’t thinned enough. Duratec topcoat is a high solids clear, it wants to be dumped on. It does also like to be thinned a touch for spray application, 10-15% is perfect. Use pure MEK if you can’t get the Duratec thinners (which is essentially just MEK and a bit of toluene anyway).
Tip to the wise, you will not get a perfect finish off the gun if you’re spraying Duratec out of a cheap HVLP gun. Even a good quality HVLP will come out peely, much better to use a conventional type air cap or even an LVLP, these will spray it on extremely well with a bit of practice. 1.8mm fluid tip for smaller parts, 2.0mm tip for larger parts. Getting enough fluid on is key.
Not bad advice from Harrisonaero either, watching pro’s is always the best way to learn. Be aware though that Duratec topcoat is not a regular paint system, it is closer to a gelcoat. A lot of automotive refinishers won’t get the best results out of it straight away because they are used to regular automotive coatings.
Does thinning with Mek change anything like flash times or gel time? I’ve never used it to thin but maybe it can lay flatter if I thin a little depending.
I used this cheap gun for adhesives and never truly broke it down and cleaned it regularly. It was so cheap and simply considered it a throw away. The companies I worked for always provided some really nice guns and I never had this outcome. However I did break this gun down and clean it, just to have an inconsistent spray. I only used this product post mold and used some nice equipment for the process so I’ve never had experience with it post mold. I’m looking at getting a lvlp gun right now. Also I wasn’t using any MEK as thinner, which might resolve my issue with the inconsistent spraying from this gun. Thank You for the advice room, I’ll save the beers for my fridge and take another swing at this with a new lvlp gun and some mek should do the trick. �� Thank You everyone. I will post pictures for you folks in a couple days once the issue is resolved.
That will sort it. The inconsistent spray will be 100% due to viscosity. Out of the tin the stuff is more suited to brush application, it needs to be thinned for spraying.
Infused, as with all coatings, thinning makes the flash time a little quicker. No effect on gel times. You don’t want to be thinning it so much that you develop solvent pop or anything like that, but I’ve thinned up to 40% without any issues so you’ve got a fair bit of leeway.
Rule of thumb, if it’s between 25-30 degrees then thin 15%. Warmer than 30 thin 10% (don’t recommend spraying if it’s warmer than 35). Cooler than 20 then thin 20-30%, but don’t spray if it’s colder than 16.
Do you think it will help lay flatter too?
Thanks buddy, I’m taking the notes.
I bought some goodies for cheap from the hardware store, and some MEK. Hopefully this should help us out getting a nice clean spray. It’s probably over board, but anything to help out in the long run.
Absolutely. The thicker a material is, the worse it will orange peel because it doesn’t atomize as finely. So the more you thin the stuff, the flatter it will spray. But you need to be careful that you don’t thin it so much that it runs easily.
Awesome. I’ll try thinning by 10% first and see what happens. If things get screwed up I blame you, haha jk
I spray the duratec out of a cheap Horrible Freight HVLP gun. I drilled the air cap to close to 2mm. It works fine but you do still have to lay it on crazy heavy. I am going to try thinning it some and see if I can cut down on the sanding after it cures.
Don’t underestimate the importance of a good quality spray gun in getting a flat finish. I sprayed this stuff for years through a HVLP gun that is actually supposed to be good quality (same gun that Fibreglast sell). I just accepted the finish I was getting off the gun and decided that was simply how the Duratec sprays. It is only recently that I got a Devilbiss for spraying regular 2k’s and decided to get a 2.0mm tip for it to try spraying the Duratec and discovered that in actual fact this stuff can spray down better than most competition level polyurethanes.
TL;DR, nothing wrong with using a cheap HVLP gun, but you are going to have to do some sanding if you want a flat finish.
You definitely have the dry spray technique down, which, is a good thing when spraying this. If you get it too wet, too quick, you get fisheyes. It’s a lot different than spraying an automotive type clear. I’m nowhere near having it perfected. It’s great for the pinholes but the fisheye thing is making me batty at the moment. Going in for my 3rd round on a part today, filled the pinholes easily but keep rushing my wet coats and making a lot of work.
If you are top coating, it certainly shouldn’t fish-eye unless you have a lot of porosity…
When I’m top coating I spray it much like a normal automotive coating, but at higher pressure and with plenty of fluid.
Makes sense to me. But I’ve definitely struggled with it acting like fisheyes. First coat there was the filling of pinholes, sprayed it and brushed into the spots, they filled fine. Then sanded back with 180 to where there are no pits left and no bare carbon spots and sprayed again, starting with a light dust coat that I allow to sit for a few minutes before going to a normal wet coat. Then I get the fisheyes again. Maybe the cooler temps and the high viscosity are getting me. It’s been in the mid 60’s temp and high humidity. Actually I am going to do my 3rd round of sanding today to get rid of the mess I made yesterday with the fisheyes. I’m thinking of using regular clear over it this time as I am very confident of getting to lay smooth. I really need to ship this part.
I’ve gotten good results before but have fought against this condition every time. Always have to sand and polish to get great results but do end up with them.
Today’s update, sanded back with 180 on a DA then hand blocked with 220. Then sprayed 3 coats of 2K clear and it laid down perfectly. A little denibbing and run a buffer over it and ready to go.
I’m wondering if I should do an application of sunshield, sand back and then 2K. Might be the quickest way until I get the knack of spraying the sunshield.
Do you have WD40 in your shop, that’ll cause your fisheye problem.