Prepping aluminum for primer / paint

[sberl]

Hi all, we have the hull stripped to bare aluminum ready for painting. I have a couple of concerns however. For the stripping process we just used paint stripper and a putty knife to scrape the paint away in the flat areas. Around the rivets we used a wire brush to remove the paint instead of a putty knife. That left a thin paint film which was removed with some acetone and a little elbow grease. In the picture below you can see the area around the rivets is a nice silver color whereas the areas where we just used the putty knife has a slight golden color. I'm wondering if the areas with the gold color will accept and hold the primer/paint?

Next, in the little red box you can see a darker area between the rivets, Is that ok or should that be cleaned up as well? I know ideally it should be cleaned up but there are probably hundreds of areas like that. Just wondering if the finish will be able to stick in those areas. I plan to use the "tractor paint" method.

 

[Scott Danforth]

3M scotchbright pads
the moment you finish, wipe with prep-sol
spray with self-etching primer
then the tractor pain.

 

[sberl]

Thanks Scott! Just so I'm clear, with the 3m pads - is that to scuff sand the entire hull, or to clean those spots up that I mentioned?

 

[Watermann]

That green is the factory AL primer, most likely alodine and it is tough as nails to get off but now that it has been somewhat compromised by the stripper I wouldn't paint over it. I've painted a few boats and one of the things I do is use a palm sander with 220g to lightly sand the entire hull after stripping the paint and that takes off any remaining green. This breaks the surface tension and roughs up the surface some giving the self etching primer more to bite into. After sanding I wipe the entire hull down with cleaning vinegar which is very acidic and finish with a clean water rinse and dry with a lint free car wash towel.

One of the best things to take off the last remnants of primer and paint is the 3M scrub pad with the handle and Jasco 5 min paint and epoxy remover.

So what boat is that your working on?

 

[sberl]

Thanks Watermann, so the jasco and 3m pad will remove the remaining primer. Then scuff sand with 220 and wash?

Ive read many posts from you and Scott and value both of your expertise!

As for what I'm working on - I actually have a restore thread going but don't usually get many answers to my questions in it. It's a 1987 Mirrocraft Northport Troller. I'm a little behind on updating my thread but the trailer is mostly finished and as the pic above shows I'm pretty close to painting the hull.

Here's the thread:

http://forums.iboats.com/forum/boat...mirrocraft-project-what-did-i-get-myself-into

 

[Watermann]

Yeah I hear you on the thread visits/replies, little tin boats seem to get swallowed up by all the glass boats in the general resto forum. One thing that helps a bunch is to add your rebuild thread link to the signature line so when you post around the forum others can easily find it. It also helps to visit others threads and post. Stop by the Starcraft section and see some of the work being done there. http://forums.iboats.com/forum/owners-groups-by-manufacturer/s/starcraft-boats

So you know, one of the forum no no's is to make a new thread for each step in your project.

Ok, off to check through your rebuild thread, thanks for the link!

 

[sberl]

Thanks for the input Watermann, I think I now have a solid plan for moving forward! Also, I'll refrain from making separate posts even though this one produced results :lol:

 

[Frogsaddle]

Hi,
I refinished a 14 foot Mirrocraft aluminum that was painted brown about 12 years ago, and it still looks flawless. I used stripper like you, but then simply put a rotary wire brush in my portable drill, and did the entire hull. It was time consuming, but as long as I kept the drill slowly moving over the hull, it was very effective, especially around the rivets. Had to use a hand brush in the corners, but just kept jabbing it into the corners, 'til I finally got to bare aluminum. I then wiped the hull down with a lint-less rag and acetone. Just don't do like I did, and carelessly tuck that damp acetone rag in your back pocket. That is unless you want your butt cheek to turn as red as one on a monkey at the zoo! Being a cheapskate, I then sprayed it with Rustoleum white primer. (Took only two cans.) I then painted it, by hand brush, with two thin coats of Rustoleum yellow, using a high-quality tapered brush. It required less than a pint. There's a few spots where you can see a hint of primer from where I've beached it on a gravelly shoreline, but other than that the hull is still a bright yellow. Total cost for the project, (not including my time) was less than $20 dollars. Good luck.

Master Chief P.J. Anderson, U.S.N., Retired

 

[Renderwurx]

I have been researching the Scotch-Brite pads. They come in many varieties... which ones are you all choosing? I found a bunch of different kinds here... easier than looking at amazon.

 

[Watermann]

I use the heavy duty one, they're sort of color coded I think and it's the green one with a handle.

 

[sberl]

Frogsaddle: I'm happy your project turned out and still looks good 12 years later! This being my first re-do, I'm hoping it lasts that long haha.

I've been using the green pads as well but I need to look for ones with the handle. I would think it would make this "not fun" process a little more tolerable. I'm really not looking forward to more stripping and scrubbing!

 

[Watermann]

Walmart has them.