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Im using Napa Cross Fire base coat and clear coat - two coats of base coat and everything looks good- first coat of clear and everything looks good- second coat of clear and I start seeing streaks in the rear quarter panels and doors- not in the roof, hood or deck lid --no runs or sags in the clearcoat - looks like the base coat silver is somehow bleeding -- how can I prevent this from happening?
Sounds like your base coat may of not been dry and its being reflowed by the clear .
Usually happens on the Horizontal panels before the side panels .
Or you had tiger stripes in the side panels before the clear & they didnt appear till you got clear on it .
I usually cross hatch my silvers & high metallics to help prevent tiger stripes , plus my Iwata LPH 400 LV makes for easy spraying of difficult colors ;)
Take it out in the sun and see if they disappear , as if your not using 98% daylight bulbs to paint in the old style Florissant lights will pull some odd stuff out that normal sun light wont show .
thanks for the input- base coat was air dry 24 hours, but I didn't cross hatch the silver enough --I'll wet sand and try again --any other suggestions would be helpful -- thanx
fog coats?
im no pro, but thats what i always did to prevent streaking/tiger striping.
Fog coats in base clear system will make your clear a bit more pealy , as the dry base will not let the clear flow out as much . And if to dry of an application the clear will look like you just painted over sand .
24 hours dry times between base and the clear coat may become a problem of non adhesion and cause the clear to de-laminate from base later on , if you didnt use an inter coat clear and lightly scuff before clearing , Because the clear has nothing to lock onto , due to the base being dry .
I shoot wet on wet .
May try to use a faster reducer to help lock the metallics if you think you can get away with it .
May try turning your material knob in a 1/2 turn to a full turn to help .
Try faster and smaller overlaps may help with the widest fan setting .
I do not know what type gun you are using , but Gun air pressure can help too , not going to drastic in either direction . Some HVLP's dont like lots of air pressure .
Some silvers can be a real bitch to lay out nice , due to no pigments in the formula .
Sounds more like tiger striping or mottling than anything else.....A smooth even base is what is needed, lay it on in overlapping wet strokes and allow it enough time to flash. Most problems with silver metallic paint is that people either do not give it enough overlapping coverage, or that they do not allow sufficient time for the base coats to fully flash over. As Spray mentioned above, using the proper reducer for your weather conditions (are you spraying it in a booth, or out in a garage?), humidity, temperature, etc will help lock the metallic base in place..........Using the right clear (the new speed clears are great) for the same weather conditions will help as well. For spraying base coat metallics, I use a SATA 3000 Digital, for spraying the clear coats I use the SATA 3000 RP Digital (also use this one for single stage "poly's")....Quote:
Originally Posted by machineworks
Bill S.
good to know!
Did you scuff the base coat before spraying? 24 hours means the base was fully dry and therefore the clear cannot bite into it to hold. The lines sounds like tiger stirping to me, not enough overlap. If anything, I'd listen to whatever SprayTech has to say or offer. Before I ever got into doing auto body and paint as a career, SprayTech taught me a LOT of things and everything he taught me I actually tried hands on and it worked for me and I still use his techniques or what he taught me today. As for gun, I use the Iwata lph400 as well and it works awesome on clear and base coats. SprayTech, when you use the Iwata 400 for metallics, are you using the purple, orange or silver cap? Orange is their new cap for kandies, flake, etc and the purple is the base cap and metallic, silver is clear but I've shot base out of it and it worked fine...