Introduction+Fiberfill primer questions

Good morning , new to the group

I’m in Kentucky and have been following learn autobody for months now and have a 05 s197 that I had to do a motor swap due to the original car being totalled by my dad.
So ive been following Tony’s series on body and paint. I’ve completed the body repair and moved on to coatings and I picked a polyester fiber fill filler primer and finally shot it over the weekend . I was having some problems with it coming out of the gun in fact I couldn’t even get it to go through the cone filters at all. so I thinned it out and to a 5 to 1 ratio and it would finally shoot.
I’ve never painted anything other than walls in my homes so it’s new to me.
The texture was very rough but I got good coverage. I think in part I had a cheap $60 gun from Amazon that sucked. I could only get about a 4 inch fan pattern.
So I’m wondering if this was normal and if not should I be concerned about adherence. And should I recoat with a straight primer after I block the polyester?

I did order a atom x27 Sunday to use for the paint.
I also had some bad water issues and am going to build a water trap in the next couple of days.

Any input is welcomed

Your gun was part of the issue. I dont know what setup you had and what materials you used. You would have been better off with a harbor freight $10 hvlp gun. They have about a 8-10 inch pattern. I dont know what pressure settings you used. You want to open the fan up to a nice oval pattern and the material up all the way up. set your pressure at the gun to 30psi. make sure you have a small filter at the gun under the regulator at the gun. I have no idea what compressor you are using but at the compressor attach a good filter / regulator and set that regulator to 80 psi. from there run your hose to the gun. This is a ruff idea you will need to look at the spec sheet you get with the materials you use. As for what you have on there you said you have very good coverage so just sand it smooth with 400 and lay your base coat. You should not need to primer again. The material on there now will act as your sealer. If you want to test it, then just spray a small area first to make sure there is not a bad reaction to your new basecoat or single stage. Make sure you mix your material according to the spec sheet for the exact materials you are using. Overlap your patterns 50% - 75% when you are laying the paint. If is is solvent based paint then 50% if it is water borne then 75% overlap. There are so many factors I dont know about, so this is about the best anyone can tell you with so many unknown factors. Good luck hope this helps a little!

Good Morning

I,ve been reading all posts and use what I can but never asked or replied, I’m from South Africa and I’m actually a mechanic but can do also auto elect and panelbeating/painting.

One problem I have is when I use primer filler the filler blocks my sand paper when I start to flat. Dry sanding are impossible but wetsanding works better. I’ve sprayed thin coats with about half an hour dry time inbetween then it looks and feels completely dry before next cote, I’ve sprayed two thick coats with an hour dry time inbetween and everytime left it for about 24 hours before sanding but the sandpaper blocks with material.

I’ve sanded with 60,80,120,220, and followed the mix instructions on the can to the letter, I’ve used the filler and hardner from same manufacturer, I can put the material on rough or smooth, I’ve tried mixing with thinners and without but the final product doesn’t seem to dry enough for dry sanding or wet sanding.

Can you please tell me where I go wrong because it is really frustrating as I’m a bit of a perfectionist and want the job to be 100% when I’m finished.

I thought about getting one of their guns but me thinking you get what you pay for lol
This gun was so terrible.

So it does send well and comes out pretty flat and smooth so I’m happy about that. I installed a water trap to completely eliminate any water. I’ll look into trying to get my compressor pressure down. Right now it’s at 150 psi. But I do have a regulator at the gun as well which I started out at 30 psi but ended up having to crank it up to 40-45 to spray this stuff.
Hey thanks for the help.

Only thing I can think of is it’s a 4 to 1 two part system
I did thin it out at a 4 parts primer 1 part catalyst and 1 part lacquer thinner. Then rough sanded it with 320 dry on the DA.
then wet sanded with wet sanded with DA and 320 and washed it down with 400 wet sand by hand. Not sure I needed the 400 wet but wanted to make sure it was flat and smooth for base.

Hi James

That is the problem, mine is also 4:1 and if I put thinner or not it never dry good enough to dry sand it, it is supposed to make dust when you dry sand but it just clogs the paper up. Even when I use waterpaper with water the paper clogs up but not as much. It seems as if the primer dries of to a point then stops, I’ve put more hardner and less hardner, I’ve parked it in sunlight and around here it gets about 40 - 45 degrees and I can leave it for a week but it stays the same

Bad material, get something different!

It may have a shelf life. But I’ve heard some others have a problem like that too.

Last time I used a polyester filler I sprayed it with a Iwata AZ3 with a 3.0mm tip, couldn’t get it flow right with a 1.8 or 2

Thanks for the reply, perhaps try another supplier, was my thought also because I had the issue now with 4 different cans.

Not an expert here but here what I have done: I use Evercoat Slick Sand so Fiber Fill may be a little different just check the tech sheet on it. I use a Devilbiss Finish 3 (new models are 4’s) with a 2.2 tip. Remove any filter screen from the gun, and if your using a pps type cup system, remove the filter screen from the lid as well. Turn your gun pressure up to about 28-30 psi. When mixing add the hardner (4:1), then add 10% acetone (not reducer). I know acetone is the thinner/clean up solvent for slick sand but not sure if it is used for fiber fill. Check your spec sheet. You have to work fast with this stuff, it will start to harden in 15-20 minutes, so only mix what you can spray in that time. This includes the gun. If you leave it set in the gun it will harden like a rock. Be sure to rinse the gun with acetone as soon as you are done spraying each batch. In my experience using this method has laid the product evenly with a slightly rough surface (about like a 220 grit sandpaper). Once dry I guide coat it then block sand it with 220 or 320 grit. Once it is flat I spray it with 2k primer. wet sand it with 400 grit, tack it and it’s ready for base coat. By-the-way if you plan to pour the fiber fill through a paper strainer , you will need a different mesh size than the ones you get at the paint store. HF sells the larger mesh size (I think it is a 80 but not sure) 100pk for $5. Hope this helps.

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