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metal sign blank/prep w/?
Hi gang, i have a job where i am going to use 1-shot paint on a metal sign blank…. I know if i dont prep it w/ something like possibly brillo padding the surface the paint will scratch off fairly easy. Any suggestions.
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3 Replies
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Hi, i take it u will be using an aluminium sign blank? If so yeah use a brillo pad or scotchbrite to key up the surface.
It is recommended you use a etch primer before applying your top coat.
Also i find 2k (2pac like the rapper! 😀 ) the best sort of paint as you have to apply hardener to it.
This ensures the paint goes off well and is more durable than standard cellulose paint. Hope this helps?
Joe
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Righteous, I will definately check into the paint… thank you for your fast response,
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quote Cookster:Hi, i take it u will be using an aluminium sign blank? If
It is recommended you use a etch primer before applying your top coat.Also i find 2k (2pac like the rapper! 😀 ) the best sort of paint as you have to apply hardener to it.
This ensures the paint goes off well and is more durable than standard cellulose paint. Hope this helps?
Joe
Spot on with the 2K etch primer. One point to be aware of though, firstly etch primer as its name suggests contains an etching agent usually acidic in nature, and secondly, some 2K products can contain isocyanates. So make sure that when using these products you check out the material data sheets carefully and know exactly what you are using.
Abrading the surface gives a good mechanical key, and removes the surface oxide layer, but you have to make sure that the painting step is carried out asap otherwise it ‘grows’ back before you can say ‘Where did that bubble come from?’ 🙁
Aluminium gets its good corrosion resistant qualities from its tenacious oxide film that forms instantly on contact with the atmosphere. Its this film that can lead to poor paint adhesion if not removed prior to painting.
Another good idea is get the balnk treated with a chromate conversion coating (Alocrom 1200 for example), or (Alodine1200 which is its USA trade name) before painting. Any local surface finishing house should be able to do this, or alternatively, buy the blank already treated! Much cheaper option than anodising and a lot quicker!!
hope this helps
(:)
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