-Need Suggestions- Paint

I have a tin I'm in the process of painting, I was wondering if I need to strip the old paint down to bare aluminum, and prime with zinc chromate, or since the paint is in good condition, just scuff and spot prime with zinc chromate, followed by paint. I want to do whatever gives me the best adhesion.
Thank you

just scuff and spot prime with zinc chromate (or other primer), followed by paint.

the most common source of paint adhesion problems come
from contamination such as grease, oil, silicone film, and other stuff.
after scuffing and sanding - clean with a solvent prior to the primer and paint.
assuming you are going to remove the decals, ensure all the adhesive residue is removed as well.

if you have access to a power washer, it would be a good idea to go over the hull
at a very close distance to remove any loose or scaling paint.
sometimes paint will look and feel solid, but, when hit with 3,000psi it shows another story.

Ok, so to summarize, I'll spot prime all bare aluminum and scuff up the previous paint with 220 grit paper and then wipe with mineral spirits. And roll on the paint.

Yeah. I would do a vinegar wash to clean the bare spots before primer. Looks like you have a decent looking boat to start with, bet it comes out good!


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I was adding this edit this morning and lost my connection . . . . .


painting over existing paint is not as crucial as painting over a new or bare metal surface.
all primers and paints need a "tooth" to hold it firmily to the project.
a successful paint job will hinge on your preparation.
an industrial strength cleaner/degreaser such as Simple Green, Purple Stuff, TSP, etc before
you start sanding - then again after you are done - then the solvent wash - and finally the
etching on the bare spots with either vinegar or OSPHO.
use the "search" feature and you will find tons of good advice on how to paint your boat.

Read, Understand and Follow the instructions on the label of all products you use.
Pay particular attention to the safety notes and heed the warnings accordingly.
any rags used in the prepping/painting process that have solvents, oils or paint on them,
should be layed out in the open to completely air dry prior to discarding them.

Note: it has been discussed in other forums that Self Etching Primer
is designed for bare metal only . . . . if it is applied over a painted surface,
there is the inherent risk of the S.E.P. tunneling and burrowing under
the existing paint to create an avenue for corossion.

Maxamillion said:

I have a tin I'm in the process of painting, I was wondering if I need to strip the old paint down to bare aluminum, and prime with zinc chromate, or since the paint is in good condition, just scuff and spot prime with zinc chromate, followed by paint. I want to do whatever gives me the best adhesion.
Thank you

Click to expand...

You keep asking about paint and the existing paint being in good condition... I'm pretty sure that is a vinyl decal and not paint. Am I wrong?

Yeah, that looks like to be applique decals.

Personally, for prep work, I remain VERY impressed by the vinegar wash! That's all I use now for prep ... the v-wash, prime (ZC) and paint. Paint adheres incredibly well!

Looks like decal (wrap) to me. I had this PLUS paint over my tin when I bought it. I used some Jacco paint stripper (real thick stuff) and Aircraft remover and brushed it on and let it sit for a bit. It started to peel and bubble and was fairly easy to remove and peel. You can see the process in my build here:
https://www.forum.tinboats.net/viewtopic.php?f=21&t=33272&start=30

Its about 3/4 down the thread.