Painting Aluminium HELP

[Gregwalker1981]

Hi guys,

just spent the day sanding my ally boat down,

now ive made my mind up instead of wrapping it and gonna paint it

i can spray a little gates and steel beams most things in my workshop

but ive never sprayed ally

i know first i need to sand and clean
then an acid etch (is a 1k acid etch ok or someone send me a link to it)
sand and etch again
then my top coat i'm going for a dark blue is there a type of paint to use
my paint supplier is ok but id ratter ask yous
sand again and apply top coat again till im happy with finish

last a sealer which has got me as i dont have a clue here
boat with sit in the water for 6 months of the year then on a trailer

any help would be great guys

cheers

greg

 

[Barking Mat]

Go talk to whoever you choose to buy the paint off, and ask how they recommend you do it.

Ideally the brand of paint , the etch, primer, will all be specified by the company in a downloadable pdf...

Don't take risks, dry, dust free environment, PPE.

 

[James1979]

Go talk to whoever you choose to buy the paint off, and ask how they recommend you do it.

Ideally the brand of paint , the etch, primer, will all be specified by the company in a downloadable pdf...

Don't take risks, dry, dust free environment, PPE.

This. Personally I think wrapping it in Realtree would be better!

 

[tom2207]

all the Canadians dont paint alloy boats , if they do its just the wheelhouse. Something to do with corrosion under paint scratches I think.

 

[julianf]

Isn't epoxy primer the current way to go?

 

[500e]

French don't paint theirs either, stray electrical currents cause real problems
Couple of links
https://www.mig-welding.co.uk/forum/threads/aluminium-jaguar.42384/
We also use these 2 products to slow down corrosion on alloy helicopter blades

 

[brightspark]

2 k acid etch primer on ally

 

[Hood]

If it needs painted right away then it needs etched but the way we usually do things is let them weather for at least 6 months then just paint without etching.
I have done modifications to wheelhouses on 20-30 year old boats that were in perfect condition under the paint, the wheelhouses on them had been made as the boat was starting to be built so sat outside in the salt air for 6 months before it was fitted then painted.

 

[Gregwalker1981]

If it needs painted right away then it needs etched but the way we usually do things is let them weather for at least 6 months then just paint without etching.
I have done modifications to wheelhouses on 20-30 year old boats that were in perfect condition under the paint, the wheelhouses on them had been made as the boat was starting to be built so sat outside in the salt air for 6 months before it was fitted then painted.

the boat is about 10 years old now just feel as it needs a Freshen up

so no etch required you think

cheers

 

[northwest]

Something to do with corrosion under paint scratches I think

The worst thing you can do is wrap it or do a bad paint job. By the time you have worked out it is corroding behind the covering, it is too late. Just give it a rub over with some scotchbrite, sorted, new finish :-)

 

[Hood]

the boat is about 10 years old now just feel as it needs a Freshen up

so no etch required you think

cheers

If it has a nice oxide coating then a wash down to get rid of salt/dirt and then paint should be fine.
Personally I would leave as is but everyone has their own thoughts and likes, I much prefer to see bare Aluminium.

 

[steveo3002]

im no boat expert but i dont see a coat of 2k etch hurting it or making it worse , last thing you want it adhesion problems

 

[Barking Mat]

Why paint it?

 

[brightspark]

the boat is about 10 years old now just feel as it needs a Freshen up

so no etch required you think

cheers

well if its getting painted yes . its needs the etch on ally as its bad to key too . paint without and just go over it with a coin and it will chip and scrape of easily .then u will feel sick in a few years time when u have to remove it

 

[julianf]

I mentioned prior, but pretty much everyone is mentioning etch, when, certainly from the datasheet, an epoxy would also work -

https://www.google.com/url?sa=t&sou...FjAAegQIARAC&usg=AOvVaw0IcFmcX0yUBElW5_x4hKtq

 

[Dcal]

I'm in the why paint it school.
But, if you must as @julianf said use epoxy and follow the recommendations from your chosen paint manufacture.
What Julian linked to is as good as any and the TDS gives you the advice you are after in one sentence

"Aluminium and light alloys:clean and degrease with 00695 SILICONE REMOVER SLOW. Sandblast or sand carefully."

If I’m doing a full referb on wheels, I get them dipped to remove the old coatings then -

Blast with fine media (Jblast that’s been through the pot a few times)
Epoxy primer,
Fix any scrapes etc,
More epoxy,
2 pack primer,
Guide coat,
Sand,
Base coat and clear.

The only thing that will take that off, if done to the paint manufacturers recommendations, is a kerb or other mechanical damage.

 

[julianf]

Dcal, you mention 2k primer (I'm assuming somthing other than epoxy) between the epoxy and base.

Can I quiz you about this? As you know, I know nothing, so I'm wondering as to the additional primer type?

 

[Dcal]

I like and have used Max Mayer 3011 2k primer for years.

Max Mayer is the cheap end of PPG and I am certain 3011 is the same as the expensive PPG Prima primer I was using at 25 years ago when I used to do a lot more painting. Paint move on and I'm sure they have something even better (and more expensive now)
I had a break for over 20 years because of life, work, kids, no workshop, no time etc. and have really only got back into it a few years ago, so absolutely no expert but I know what works for me in a diy setting.

https://buyat.ppg.com/Refinish_SSA/...lCode=44&PdfId=23201&ProductCode='1.856.3011'

The reason I use it is it’s what Fiat and Lancia used on the cars I like to work on (80 – 90 italian scrap) and it works.
It's, adaptable, quick to dry, lovely to sand (wet or dry) and gives a great surface for top coat.

If you read the data sheet on the Lechler they don’t even pretend it's nice to sand and damn it with faint praise ("Fairly good sanding") but it's no different to other epoxies which are gummy if not fully hardened and hard if they are.
If what you are working on doesn't need a lot of sanding then epoxies are great (and far better as a proper primer) but most of the stuff I work on does.

Others will have better systems and advice but I can only say what I know works from my experience.

 

[Gregwalker1981]

So I’m just gonna scotch brite the ally now. See how I get on

 

[Hood]

So I’m just gonna scotch brite the ally now. See how I get on

Before painting or just you are going to do that to spruce it up?