That can’t be done. A matte coating sprayed into a gloss mould will come out glossy. You need to either post-finish with a matte coating, or you need to make your mould matte. Number of ways to do that like light misting of PVA, scuff with 2000 grit sandpaper etc, but the best way is just to make your plug matte and pull your mould off that.
Did two little test today. The parts are actually in the oven curing as I type this. The orange mold was PVA’d and then I laid on a medium coat of clear, then a heavy coat. No fish eyes for the most part. Some dust landed on the surface making it look not that great but should disappear in the part as it wont be the surface. The two squares on the mirror are prepped with ChemTrends mold sealer and PMR EZ90 release. The left square I put one quick coat of wax on first. I did 2 dust coats, then a heavy coat with about 5 min in between. I’m testing for a production environment so don’t want to have to wait forever between coats. But you can clearly see that the side that was quickly waxed didn’t fish eye. I’ll do a follow up once I demold them. The orange mold part was vacuum bagged, and the mirror parts will just be a wet lay. Just want to test a few small things before I go all in on infusing something.
Edit: I’m using an automotive 2k clear that I had laying around.
IMG_0162 by AJ Hartman, on Flickr
IMG_0163 by AJ Hartman, on Flickr
What’s the result of your test? thanks!
Interested in results as well.
Make sure you try trimming the parts and sand the edges with a course file. Also maybe give them a good twist or deflection. Something to put the part under a good amount of stress.
I’ve had a lot of problems with delamination when using just a regular 2k clear coat in the mould.
Made many tests and some IMC items,but can not put 100% perfect layer. Only thick IMC looks perfect.
So i think about spray gun…please give a few specific gun models , which gave good results with epoxy IMC .
Update from my post a few posts up.
Its almost hard to tell in person so probably cant be seen on the pictures, but the No Wax plate almost had these “ghost circels” where we were actually looking at the epoxy instead of the clear coat. There was an ever so slight different look to those areas. These first tests were just simple wet lay at the time as I didn’t want to waste time and materials bagging them if it didn’t work out. You can see some very small voids within the laminate. Since the No Wax clear fisheyed so bad, there were some pin holes in the part. My next test was cutting. The two methods I mainly use are a fine tooth band saw blade, and a dremmel with carbide wheel. I cut the part face up, along with the part face down. The face down cuts with the band saw were the worst as the teeth must have almost chipped, or pulled away the carbon and chipped the edge of the clear. I did do an actual part as well. I made some hood louvers for 13-14 Mustangs with this technique. Our parts always came out of the molds looking pretty good, but the clear does add that little extra. You no longer have to worry about the haze of the spray tack. I ran out of infusion epoxy so the clear actually cured for almost a week before I infused the louvers. Obviously not ideal, but there didn’t seem to be any terrible adhesion problems during cutting or sanding. Two little areas the clear seemed to peel up if I didn’t cut fast enough with the dremmel it seemed to over heat the clear. But I under cut the part on purpose and then sand to the line. Either way, a good test. Decent results with a cheap 2K clear that has been sitting on my shelf for about 2 years atleast.
Edit: since I had a non clear coated part for direct comparison, I was able to calculate that the clear in this method (2 light mist coats, and one heavier coat) added about 5% to the parts weight. Not terrible, but I mainly focus on race spec parts, and its still weight.
Does anyone have any other before and after weights of clearing methods?
IMG_0208 by AJ Hartman, on Flickr
Close up of band saw cuts face down.
IMG_0210 by AJ Hartman, on Flickr
First test part. Made with infusion. In the reflection you can see the difference. Cleared on left, no clear on right.
IMG_0216 by AJ Hartman, on Flickr
Full shot of the parts. Not in reflection, and being about 2 feet away, you can’t even tell the difference. I’m pretty sure I remember the cleared parts being on the left.
IMG_0214 by AJ Hartman, on Flickr
What spay gun do you use during IMC ?
The cheapy cheap mini gun from Harbor Freight. I have a decent larger gun from my days doing body and paint work years ago that I can use for larger jobs.
Man. I just read this. It would have saved me a bunch of parts!
I as well have issues with a 2k automotive clear for an IMC. I wanted to change techniques since I’ve been using per your recommendation sunshield topcoat. Sometimes though it tints my parts a slightly. Which up against something that’s sprayed with automotive clear you can see. It’s not so much if I prep the parts and spray duratech after I demold and trim but it tends to be when I IMC duratech. Maybe I’m just loading it on to much in my mold vs spraying on the part…
Anyways anybody in the US have a good hard 2k automotive clear coat? They’re fine if you spray afterwards but I did a few imc coats on parts and de molded a part today. The clear was semi soft still and it delaminated the entire thing using compressed air getting under the edges.
Since I did these parts in batches I forget if I let one cure more in the mold than another.
If you have a smaller mould you can use as a test and don’t mind wasting a bit of material on, I’d suggest try spraying the IMC and let it cure. Then sand it with 180 grit paper, making sure you get a good key all over the surface even in tricky areas. Even go down to 120 or 80 grit at the edges and anywhere that will be trimmed and filed, just be careful not to go through and damage your mould.
This should enable you to use virtually any coating in mould. I’ve had success doing this for producing factory colour matched parts straight from the mould, as well as more simple clear coated carbon parts.
Ah ok. Makes sense for mechanical grip. That most defeats the purpose of clearing in mold almost haha. I’ll give it a try though. The part is kind of large 2 feet by 3 feet… Thanks for the tip again man!
Yeh it’s a bit more tedious, obviously much nicer to have a proper IMC. But for me the advantage of an IMC isn’t so much in avoiding the prep-work, but more in the consistency. You can spend 10 hours getting the mould absolutely perfect, and then pump out absolutely perfect parts with 0 orange peel everytime, without the need for fiddly processes like flow coating.
Having to sand the IMC or gelcoat first does add a bit of time, but it’s still nothing on post-coating. Plus you know the surface will be perfect without the risk of orange peel or runs or debris, etc. Still the better option in my opinion!
Very true. I typically IMC with sunshield on this one part but somehow screwed it up even though I’ve done it many times. I had to strip the part twice because the first time I sprayed duratech I had fish eyes from not properly cleaning, then I just resprayed and wet sanded. I had a ton of orange peel since my gun was trashed and just bought a new one. It took hours…
Needless to say I’ll be standing my molds that I use 2k in.
Did you ever do a test with waiting a week or so with added heat to make sure the 2k clear was completely or as cured as possible?
Guys,
I am really about to give up on In Mold Coating of Sunshield Duratec…
See attached picture:
I tried:
semi-permanent Silicon based EnviroShield
Wax TR104
EnviroShield+ Wax TR104
Tried everything…
- 1x Really thin spray, 10min wait IR light, 2nd layer really thin spray
- 30min Wait IR light
- 1x medium spray
- 30min wait
- 1x heavy spray
…
And pretty much any other combination, but no mather how many thin layer I spreay and how much I wait in between: As soon as I spray a wet coat I get the result in the picture.
I purge my compressor, have a water/oil seperator on the line. My Duratec is almost brand new product…
Anyone here who actually is doing this on a regular basis with success with those types of release agent??? I really doubt it is possible.
Tks…
Otherwise… Who is actually doing true in mold coating with Duratec Sunshield and with which release agent with success?
I use Sunshield as an in-mould coating all the time with great success. Frekote 770-NC semi-perm is the release agent that I normally use, but haven’t found a release agent yet that I can’t use it with.
That said, are you referring to the Zyvax Enviroshield? If so, that is an extremely high slip release agent. Even compared to other high slip release agents it is definitely very high slip, so I’m not surprised you’re struggling.
I would suggest not using Enviroshield with any in-mould coating. If you need high slip, I would suggest Frekote or Easylease or Marbocote, or any of those types of release. If you don’t necessarily need high slip, then have a look at the Zyvax Flex-Z range. The Z1 makes applying Sunshield so easy it’s almost no fun anymore. It will start to fish-eye again with Z2 upwards, and Z6 can be pretty damn difficult, but it is possible.
When you say “really thin spray”, how thin is it? I mean, I have to mist it on. Barely coming out of the gun and barely anything on the tool as my first “coat”
You don’t have enough wax layer blocking the chemical release agent. What I mean is the chemical release agent makes your IMC bead up like that. You need to apply more layers of wax until it stops. I typically let my mold sit in the sun, wax a few times and then put it inside. The sun helps speed up he process of drying the wax because I’m impatient.
This works well if you do a lot of wet sanding and post finishing. Not to sure how it works if you are trying to get perfect finishes right out of the mold.
to Hanaldo:
I think your are spot on. The water based silicon Zyvax Enviroshield is way to slipery. I now want to move to Frekote 770NC.
Q: How do you best (and most importantly “quickly”) achieve results with Frekote 770NC and Duratec? Only 1 light dust coat of Duratec and wait 5-10 min for flash (under IR)? Then apply wet coats? Do you apply 3-4 wet quotes? Tks!!
to Dannyhockin and Infuse:
Do you use Enviroshield and Duratec on a reliable and reproducible fashion (not exceptional basis)? I tried multiple times with extremely thin/dry/dust coat barely triggering paint. I even tried with 3 distinct of those dust coats with 10-15min of IR in between. Then Medium coat but then as soon as I put wet coat here goes the fisheye. And yes I tried to “Fast coat” with Wax TR104, same results. And I cant spend 1-2h to applied X amount of additional coats of Wax to block the Enviroshield release agent, would defeat the purpose of time saving of IMC… For now, I believe that IMC is not acheiveable with the high slip of Enviroshield or Wax TR104. Frekote 770NC seems to be the favorite solution on this forum for this. I will give it a try.
Other random questions:
- How many wet coats do you guys apply to get proper UV blocking Duratec clear?
- Where do you guys source your Frekote 770NC (US or Canada)?
- Any preference between Frekote 770NC and the 700 ?
This is the technique I use with Frekote, and to be honest I think you could get it to work with the Enviroshield it will just be harder.
Do one dust coat first up using a small amount of un-thinned Duratec. Bump the gun pressure up to 50psi, and close the fluid nozzle such that you can barely see any material leaving the gun. This is important, don’t try to lay your dust coats on in a regular fashion by just moving the gun quickly - there needs to be barely any material exiting the gun.
To be honest, this should be so dry that it should be virtually tacked off as soon as it hits the tool surface, but give it 10 minutes anyway. Don’t use IR unless it is under 25 degrees. If you’ve got a booth, it’s better to get the booth temp up to 30 degrees and just work in that. Cold temperatures (below 25) are a killer for getting good results over a semi-perm.
Once this has tacked off to a ‘hand swipe’ point (you can drag your fingers across it without removing any of it - make sure you do this on a flange section!), then proceed to do the same again. Once the second dust coat has reached the same hand swipe tack free point, mix up some Duratec that has been thinned 10%, open up the fluid nozzle one or two full turns so that you can now easily see material exiting the gun, and drop your pressure down to 30psi. Now lay down a tack coat in the regular fashion as if you were post-coating a part - you don’t want a full coat yet, but you should be closing out the dust coats. Don’t panic if at this stage you start to see some fish-eyeing. Again let this tack off to the hand swipe stage - that is very important, if you can’t drag your fingers across the surface yet then don’t proceed to full wet-coats. If you do have any fish-eyeing, just dust over the top of them using the original gun settings, then do another tack coat with the regular gun settings.
Once hand swipe-able, you should now be able to do your first full wet-coat. I like to have the pressure down between 20-30psi, fluid nozzle completely open. Again, do not panic if you see any fish-eyeing, the film isn’t yet thick enough to cover these. Now you don’t want to use the hand-swipe method anymore, you want to switch to a regular tack-free touch test. Proceed with the next coat as soon as no material comes off on your finger. Do three full wet-coats. Now if you have any areas of fish-eyeing, the best bet is to grab a paint brush and gently brush over them until they close up. Once they stop re-occuring, spray another full wet coat over the top to level out the brush marks.
Once mastering that technique, I’ve never had any issues with using an IMC. I would give it one more try with the Enviroshield, making sure to achieve full film build before panicking about fish-eyeing. Realistically it doesn’t matter how slippery your release agent is, the material will get to a stage where it just can’t open up anymore. I do understand how tricky it is though, and especially with enviroshield.
As for film thickness and number of coats, it depends on how much you are thinning it. If you’ve only thinned it 10% then 2-3 full coats is perfect. If you’re thinning it 20% or more (not sure why you would be for IMC application) then you may need 4, but it is a high build coating so it does build a nice film easily.
I have been spraying duratec sunshield as an IMC every week lately.
Frekote 700NC I think
TR 108 wax
Thinned Duratec for all coats.
Dust
Dust
wet coat
wet coat
Only wait about 5 minutes or less in between coats.