newbie looking for adive on primers and clears
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Hi people, I’ve recently started a alloy wheel refinishing business and I’m after some advice on which clear to use, I work mobile and use 2 x 1kw ir lamps I’m looking for a great clear to use and also should I use 1k or 2k primers
Working mobile you don’t have the time to wait for most 2K primers to cure. I’d be talking to your paint supplier about what they have that has very short curing times, maybe the UV flash type, or possibly a purpose made wet on wet primer.
Most paint companies also have very fast curing clears. I notice that Cromax have just released here Cromax® Ultra Productive VOC Clear Coat 3760S which will cure in less than 15 minutes under IR. Something like this would probably suit you.
Hi thanks for replying, I’m using a wet on wet primer at the moment from max Meyer but I’m having trouble laying it smooth it’s landing very textured not dry but like very very orange peel if that makes sense,I tried more fluid but then it runs
When I do wheels (and I do quite a few) one of the challenges is that you get a lot of overlap as you cover the various faces of the spokes. This makes it really easy to get too much paint on, expecially if you narrow the fan to reduce wastage/overspray.
I prefer to use a smaller gun for jobs like this. Still 1.3mm but less fluid flow and naturally narrower fan means that it better suits the job. If you’re using a wet on wet primer then your substrate needs to be near perfect as the primer isn’t sanded to take up flaws. In that case the primer just becomes the bond between substrate and colour coat and doesn’t need to be thick at all. It’s the overly thick coating that is giving you the excessive OP, possibly because you’ve turned down the air a bit for the smaller job size. In my case I use a Star SMV1000F which is perfect for the job. Other manufacturers make equivalent guns (e.g. Devilbiss SRI PRO).
I use gti pro, 1.2 but large fan am thinking of trying sata 4400 mini, for exactly that reason, when you prep wheels I find I’m taking ages scotch padding the wheel in and out the small gaps etc, how much do I need to key the old clear for example is it just a light scuff quickly over or do I need to make sure every part is keyed to a certain degree?
Yes, the GTi Pro probably is a bit big. Not so bad on 5 spoke wheels, but when you get one that has 12 spokes it’s a different story. I wouldn’t use a “mini” gun. They can make the metal flake or pearl stand up differently, unless maybe you’re just doig one spoke or small section of the rim.
You need to scuff really thoroughly. Grey Scotchbrite is fine but press firmly and don’t miss any bits.
You say GreY scotch is fine , what would you say is ideal grit for adhesion but also as not to leave visible scratch marks under clear, I find the gti reasonably good size for base coat but was thinking of the sata 4400 for my clear as that’s when I seem to find the larger gun with multiple spoked wheels a problem, oh and is there a primer which I can use wet on wet which has reasonable build and a direct to metal like an etch rather than having to use two primers every time
It’s generally held that grey Scotch is the equivalent of P800 but I’ve had scratches still visible from P800 under clear. If using paper I like to use P1200 or P1500
And paint will adhere ok to 1200/1500 or is that just for clear? And is that a good enough key for say primer to stick, not that I’d deliberately sand to 1500.anywhere that would be primed but as you know wheels it can sometimes difficult to keep the primer area local
Rules of thumb:
Under primer – P400
Under base – P800
Under clear – P1200-P1500Thanks for all you advice it’s really appreciated, Is there a product that’s wet on wet primer with corrosion attributes like an etch but also some build that doesn’t require sanding, the small areas on an alloy that I go back to bare metal do they still require an etch prior to primer? Imt just thinking that because on most of the alloys I paint there’s some small corrosion areas anyway if I was to just primer under my paint instead of an etch how ling will corrosion take to come through and if by then other areas of the wheel will probably be corroded by then, hope this makes sense
An etch or epoxy won’t really stop existing corrosion, you need to remove it by sanding or grinding then build the area back up with filler. What is the MaxMeyer primer you are using? Some primers are not meant for direct to alloy.
You say you want to stay with wet on wet, but you want more build. Surely that is going to give you mapping issues? If you get more build you will need to feather the edges. Maybe best to stick with a wet on wet primer with low build and just get your prep right.
Hey sorry what I meant to try and say is that at the moment my procedure is
1, remove damage or corrosion which normally means I’m left with a patch of bare ally
2, etch primer on said area
3, wet on wet primer
4,base
5,clear
My query is I’d like to use one product for steps 1+2 rather then having to prime twice, mainly because it’s a wheel and sometimes the area can be no bigger then a inch or twoI see now. Well Mipa do a 2k transparant sealer that will adhere to bare alloy and is non-sanding / wet-on-wet. I have not used it, but heard it’s good.
http://mipa.de/gb/product/prodinfo/produkt331.html
It does recommend to use a dedicated primer for best corrosion protection, though I guess it depends on what kind of warranty you want to offer. It is probably fine for small areas and a lifetime of a few years. Given your short time allowance for the job, maybe it is just as effective as what you do now, as if you prime over etch without a leaving a good while the acid can prevent full adhesion/cure of the primer.
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