Well, that didn't work.....

S

StolenFox

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So obviously, I screwed up. The problem is that I'm not sure what I did wrong. Specs for the failure are as follows:

Gun: http://www.summitracing.com/parts/sum-02-50014
Set at 28 psi with trigger pulled per Barry's recommendation
Bare metal with 80 grit for tooth
3 passes with waterborne w&g the night before
Tacked off with a new crystal cloth. Gently waved across surface, no pressure applied.
Gun set up according to the SPI tutorial
24 oz of epoxy mixed and induced for 40 minutes
8 oz left over after one coat on the exterior of a hood and two fenders
Approx 68 degrees at 56% humidity

The hood came out very good (horizontal) compared to the fenders (hanging vertically). Only a smal bit of the same defect located in a crease is evident on the hood. The fenders are a mess! I stopped after one coat because of the issue, figured it best to not put on more material to end up sanding off. Sorry about the last pic being upside down, don't know how to fix that....

So, how did I screw this up?

S.F.
 
too wet and heavy first pass. got too close on the top of the fender. sand it down a little and be more diligent with distance and speed. you'll get there .
 
shine;28959 said:
too wet and heavy first pass. got too close on the top of the fender. sand it down a little and be more diligent with distance and speed. you'll get there .
Click to expand...

Thank you shine, I wasn't sure if it was too heavy or contamination. What grit should I use to take care of the issues and provide grip for subsequent coats? It going to be a few weeks before I try this again.

S.F.
 
shine;28959 said:
too wet and heavy first pass. got too close on the top of the fender. sand it down a little and be more diligent with distance and speed. you'll get there .
Click to expand...

x2.
I would give it a day or two to cure then hit those spots with 80, followed by 180 to remove the scratches. If it's going to be a couple of weeks before recoating, you'll need to scuff the entire panel with 180 anyway.
 
Well, the first coat can be a fine line. Too dry of an app will compromise adhesion, too wet and all hell breaks loose. The second coat can be sprayed more like a single stage paint.
 
I'd like to practice my technique on an old hood I've got but I don't want to waste SPI product. Can anyone recommend something cheap for practicing gun setup and spraying? Rustoleum perhaps?

I wonder if any of you pro's would be willing to test my gun for me to see if its worth a damn?

S.F.
 
I'm afraid that nothing else I routinely use sprays quite like the epoxy. The cool thing about it is it's just primer, so what it is doing is training you to have good gun technique, which will help you immensely when it comes time to shoot clear. The appearance of primer is not that big of a deal, it gets sanded out. So just relax and keep practicing using the epoxy, your results are nothing out of the ordinary. Remember the way to Carnegie Hall.
 
crashtech;28981 said:
I'm afraid that nothing else I routinely use sprays quite like the epoxy. The cool thing about it is it's just primer, so what it is doing is training you to have good gun technique, which will help you immensely when it comes time to shoot clear. The appearance of primer is not that big of a deal, it gets sanded out. So just relax and keep practicing using the epoxy, your results are nothing out of the ordinary. Remember the way to Carnegie Hall.
Click to expand...

Thank you for the encouragement and for putting it in perspective! After all the build up with car prep, buying and building the tooling it was sure hard to see it fail like it did. Probably pretty ambitious to think that it would be perfect given I've never painted before.

I understand that proper technique would have had better results but I wonder how close my gun setup was to optimum? Perhaps I had the pressure too low or the fluid open too far?

S.F.
 
From the looks of what happened, you might bump the pressure and slightly restrict the fluid, and move a bit faster and/or make sure you are maintaining a 6" (plus or minus) distance from the panel keeping it as perpendicular as possible. All these things work together, different guns and materials will dictate technique to some degree, but once you have settled on a spray technique that works for you, what you will learn to do is adjust the gun and air pressure to better match your style. Mainly you just put too much material out on that critical first coat.

If you continue to have trouble, I hear Barry is pretty good at walking guys through the gun adjustment and spraying process on the phone right as you are spraying.
 
I see, a combination of efforts to produce the desired result. Thanks to all for the education!

S.F.
 
Pic. 1,2,&3 look like some type of contamination to me, Pic 4 is just a run, with some orange peel around it?
It looks exactly like what I have experienced a couple of times with Waterborne over filler...
The good part is the Epoxy sands so good that it really is not a problem.
 
I've noticed that extending the induction time will help prevent those Swiss cheese looking spots. I like to let it induce over night and it seems to let me spray on a heavier coat without many issues.
 
DavidL;29028 said:
I've noticed that extending the induction time will help prevent those Swiss cheese looking spots. I like to let it induce over night and it seems to let me spray on a heavier coat without many issues.
Click to expand...

I was thinking about letting it induce longer next time, thanks for the confirmation!
S.F.
 
A big thank you to everyone for their input and encouragement! After smoothing the runs and sanding everything with 180, I resprayed the front clip today. The expected trash (from my open wood truss garage) not withstanding, the epoxy layer down very nicely this time. Raised the air pressure, induced for two hours, moved faster and let it flash 35-40 minutes between coats. After this better result I feel much more confident about taking this on.

Time to start saving for the Iwata LPH400LV as I can tell my cheapie is a primer only piece.

S.F.
 
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