I just purchased a 1978 monark 16 ft extra wide jon boat. I have replaced the transom. will be putting a floor in it and extending the deck up front. Question is. Is there a way i can repaint the boat wo taking it down to the bare metal? Can I sand the old paint and rough it up, primer it and paint?

Yes.
Wait for all this rain and humidity to pass

The durability/quality of any paint job is primarily dependent on the prep and secondarily, the quality of the paint used.

1, Clean the surface with simple green cleaner (it's the cleaner often used to clean BBQ grills--sometimes found in that section)
2. Sand with 80 grit
3. Wash and clean with TSP (trisodium phosphate)--Home Depot/Lowes
4. Sand with 180 grit
5. Wash with acetone, let it dry, and rub off any old paint that has lost adhesion with a scotch brite pad.
6. Prime with SEM self etching primer (Amazon.com) to any bare metal areas


7. let it dry
8. Apply paint primer of your choice (I'd use an oil based enamel) A good option would be Valspar Tractor and Implement primer. Amazon.com has the best price



9. let it dry
10. Buff with scotch brite pad
11. Apply paint primer of your choice (second coat)
12. Let it dry and buff with scotch brite pad
13. Mix Valspar 4625 Enamel Hardener (amazon.com) with Valspar Tractor and Implement paint (sears.com) per instructions





14. Apply first coat and let dry 4 hours
15. wet sand with 320 grit
16. Apply second coat.

k thank you sir. dont think i will get around to painting it this summer but maybe this winter. trying to get it ready to fish for the summer.

Duralux makes a semi-flat aluminum boat paint that doesn't require a hardener or specific primer.

I'd still do the initial cleaning and sanding steps and use the SEM primer on bare metal areas the Scotch Brite pad prior to applying the duralux.

It comes in semi flat green, gray, and black.

Home Depot online has a better price and free shipping

Ya might want to check out Top Secret Coatings Super marine coatings. Any bare aluminum must be etched with phosphoric acid first 3 parts water to 1 part acid. This etching process has to be done before any primer is applied (self etching preferred).

Their SM 664 D is the stickiest paint I have ever used sprays easy out of a cheap HF spray gun and is self leveling can be rolled (no tipping).

You can top coat or like I did add a layer of SM 7390 2 part epoxy primer as waterproof barrier can also be rolled (no tipping).

For top coat I applied SM 1000 revolution gloss black (127 colors available)chose finish flat,satin or gloss. I applied this with no hardner it is a rated bottom paint and would recomend using the hardner cures paint quicker. SM 1000 is a self leveling paint that can be rolled on (no tipping).

I prefer spraying paint cuts down on sanding. These paints are the easiest paints I have ever sprayed. Rolling it will leave some orange peel in the gloss. Flat and satin finish will hide the orange peel very well when rolled on. DIY guy or gals will look like a pro using them follow instructions on paint. These paints are sold by the quart or gallon (SM 7390 is 2 part and is sold by 1/2 gallon or gallon). By the way I used to be an Imron guy sprayed gallons of it. Never thought I would say this these SM paints have pushed Imron to 2nd place with me.

Here's another highly recommended paint for aluminum boats at $54/gallon (I read the .pdf instructions, it recommends cleaning+sanding+etching (can use white vinegar or the self etching primer I listed above); but no primer paint needed.

Go to lockstockbarrel.com for more info and .pdf files with instructions on paint prep and application

Comes in lots of different colors: Can spray it, roll and tip, or just brush it on

I'm a high end paint guy for good reason it lasts a long time. I personally would not use vinegar as a metal etch (I know it's an acid) I have had excellent results using acids made for metal etching. They also make self etching primer stick better.

I don't do 100.00 dollar paint jobs as they don't last very long. The paint tends to peel and chip too much for me. For me it is a simple thing why go through all the effort to prep the surface then cheap out and experience the headaches. I guess I'm just the high dollar guy it works for me. My value is not having to touch up paint, (scuffs along the way that is normal for a boat).

I did this last Fall. I used paint remover to get rid of the 50-year old paint(many different coats). I sanded to bare aluminum. I etched with 50/50 vinegar-water mix twice. Washed with fresh water, dried, and quickly primed with zinc-chromate primer(NAPA Martin-Senour spray can). I painted with Tractor Supply Majic spray can enamel. Then, I top-coated with Majic Clear Coat. Cost me less than $100, for my 12-foot flat-bottom.

Came out great. I've been using the boat in the saltwater marshes for six months, and it's holding up very well. Don't forget to use the Clear Coat. Good luck!

IslandJim

Sounds like you did a great job
Any pics?

collincountytx: If you scroll down in this forum to a post that says: "My Dad's 1959 12-Foot Flat Bottom", there are a couple of pics. I get lots of interest and compliments every time I take it to a boat ramp. He bought it for $239.00 from Leonard Bros. Dept. Store in Ft. Worth. It's bounced around the family for decades, and I got it and restored it. When I first saw it, after about 40 years, it was in a field with eight inches of water in it! They don't build them like this one any more!

IslandJim

The boat I purchased had a good, smooth, but faded base of Olive Drab Green.

This is what I did.



Then final coat




This video was helpful: didn't use any spray can products--imo, rolled and tipped gives a better result on a boat than you can get from a can. Finishing with a spray on clear enamel is a waste of time also. But, the roll on techniques and details showed in this video are excellent.

1. Strip paint with paint stripper.
2. Sand to bare metal 220 grit
3. Etch with straight vinager, keep vinager on metal wet for 10 min.
4. Rinse with water and start painting asap.
5. Duralux aluminium boat paint, best there is. No priming needed.
6. Thin with xylene for spray gun.
7. Let cure in direct sun for a few days until it passes the fingernail scratch test.

I have done this to 12 aluminium jons and the paint holds great and is hard to wear off.

I used this sanded lightly ..held up well and I rolled and brushed..came out like I sprayed it..been several years

Duralux aluminum boat paint

Duralux is awesome. Used grinder with wire wheel and aircraft paint stripper then rolled on duralux. Looked like a new boat from academy. Really impressed with duralux