Let me tell you what's annoying.... using red oxide primer as a base-coat for a tank, leaving it to dry, sanding down any slight imperfections, re-spraying any remaining bits and pieces and leaving it to thoroughly dry only to have the red oxide primer bleed through when you apply the top coat! THAT'S what's bloody annoying! It even softened the undercoat to such an extent that I got paint dribblesdown the side! Grrrrrrrrr! Now I'll have to strip the lot off and start again! *END OF RANT*
I don't know about Baufix, but perhaps there was some loose, sanded-off red oxide dust still remaining on the lantern when you applied the top coat? These could 'float' up or appear to bleed-through. Or maybe the top coat was a tad bit too wet/thick when first applied on the primer? This could also dissolve the dried binder resin of the red oxide primer and blend-bleed into the still wet top coat. I presumed that the primer is not an epoxy-based type, which would not re-dissolve when wetted with any solvents from the top coat/paint. Happens to be the Vapalux 300 here?
Yes, it's the Vapalux 300, steel tank. I have discovered that if I apply more thin layers the bleed stops so I'll gently rub down the runs and keep going. The parts of the tank where there is a good build up are very smooth, totally grey and very shiny. When it's finished it will look really nice. The colour isn't quite correct but I'm not that bothered. The brass hood was very badly corroded and pitted but after a lot of work it cleaned up well... or as well as I can get it without an ultrasonic cleaner.
Glad to hear you've got it sorted out. Very thin layers of spray paint, allowing each layer to dry before applying the next successive layer. Otherwise would be runny. We tend to try make the initial layer look shiny and fuller by applying thicker but that doesn't help and we end up with runny or puddled-up patches .
Damn, damn damn, blast and damn again! I've given up and admitted defeat! Each time I spray a little more grey on the tank the a bit more leaches through, no matter how lightly I spray it so it's got paint stripper on it again ready to be de-greased and sprayed afresh! Oddly enough, the frame is fine so I'll leave that as it is. Lesson learned, don't buy Lidl Red Oxide primer!!!!!
Its the solvent from the top coat re-dissolving the primer resin binder. You'll be better off with a 2-K (2-component) automotive-grade epoxy-based primer, which would not bleed through that way, Colin. Once its dry, its also semi-cured. That makes it more resistant to any solvents from the successive paint coats.
Did you make sure that the top coat was compatible to the base coat? The best is generally to buy both from the same manufacturer, and of the same series so they are made for each other. Otherwise it's not so much to be upset over when things like this happen. I've been there several times when I used two paints with different thinner base in them. Generally they do work together, but not always.
You are correct, the primer and topcoat were not from the same manufacturer so I have only myself to blame.
That's right. A quick look on the MSDS or SDS would give you some ideas about the contents(especially the more hazardous ones) of the paints. What top colour coating did you use, Colin?
On the can it's called dark grey and looked to be the closest grey available. There was another colour called Honda grey but it was much darker and possibly metallic. To be honest there's not a lot of choice in Fort William. I've just given the tank a third coat and it's looking good so far.
Found out that I can get any colour at car repair shops where they mix paint. Ask for 2 component paint and they also can add "anti grease/silicone" into the paint.
I personally would avoid silicones on any non-final paint jobs or during intermediary steps. If any traces of silicones were left on a surface that has not yet receive its final coat, they're likely to cause 'fisheyes' on the paint job later on. They're best left alone until after the paint job is complete and final and no more decisions to strip again or re-coat.
