Hi Folks -
First post on this forum ! I have to admit I am not a boater (yet) so please don't run me out of town with my questions.
My search for the last word on painting aluminum led me to this forum and I must say, there is a wealth of information here. I have read many posts on the subject and think I have the process figured out, but I wanted to toss up a couple of questions.
The Alumiprep data sheet says "ALUMIPREP 33 should not be used on high copper bearing
aluminum alloys or aluminum castings". My first reaction to this was "crap - I am painting aluminum castings" so I can't use this system. But then I re-read it - perhaps it is saying should not be used on "high copper bearing aluminum castings" ? It seems to me that many of you folks are using this on your motors which most certainly are made from aluminum castings and not big slabs of 6061 or such ! Am I correct on this?
Next - I have several cast aluminum pieces that are from some machine tools that I am reconditioning - a lathe and a mill. I have no idea as to what the alloys are, but there are voids and depressions in them in places now that I have stripped them of all the paint and the fillers. I will have to re-fill and smooth the surfaces as part of the re-painting process. I'll probably use an aluminum filled bondo like product. Here's the question - fill and smooth the bare castings before I start the alumiprep/alodine/ZC process or after I put the first primer coat on. I am thinking that I should fill and smooth after the first primer coat - the reason being, these fillers are not waterproof and one wants to seal the surface first, otherwise the various wash coats before you get to the primer coat, will surely soak in and remain trapped under the paint....which is not good.
That's about it for the moment. Thanks a million for all the info on painting aluminum here in this forum - it has really helped me get my head around the subject.
Cheers,
Lewis
First post on this forum ! I have to admit I am not a boater (yet) so please don't run me out of town with my questions.
My search for the last word on painting aluminum led me to this forum and I must say, there is a wealth of information here. I have read many posts on the subject and think I have the process figured out, but I wanted to toss up a couple of questions.
The Alumiprep data sheet says "ALUMIPREP 33 should not be used on high copper bearing
aluminum alloys or aluminum castings". My first reaction to this was "crap - I am painting aluminum castings" so I can't use this system. But then I re-read it - perhaps it is saying should not be used on "high copper bearing aluminum castings" ? It seems to me that many of you folks are using this on your motors which most certainly are made from aluminum castings and not big slabs of 6061 or such ! Am I correct on this?
Next - I have several cast aluminum pieces that are from some machine tools that I am reconditioning - a lathe and a mill. I have no idea as to what the alloys are, but there are voids and depressions in them in places now that I have stripped them of all the paint and the fillers. I will have to re-fill and smooth the surfaces as part of the re-painting process. I'll probably use an aluminum filled bondo like product. Here's the question - fill and smooth the bare castings before I start the alumiprep/alodine/ZC process or after I put the first primer coat on. I am thinking that I should fill and smooth after the first primer coat - the reason being, these fillers are not waterproof and one wants to seal the surface first, otherwise the various wash coats before you get to the primer coat, will surely soak in and remain trapped under the paint....which is not good.
That's about it for the moment. Thanks a million for all the info on painting aluminum here in this forum - it has really helped me get my head around the subject.
Cheers,
Lewis
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