Hello,

I have taken the fuel tank out to clean and under the tank there is surface rust which I would like to address before putting the tank back in. The goal is to clean it up and prevent the rust getting worse.
I am think of using Kurust after I cleaned the majority of the rust off then paint over it.
Are there any other products you could recommend.

Click to view attachment

Also how did the factory fit the roll bar, the PO did not do a good job of cutting the body to make way for the plate.

My method for treating rust is wire wheel, ospho, neutralize, sand, epoxy primer, paint. Sometimes I feel comfortable enough I can skip the ospho treatment but it’s good assurance. I’m not a fan of any rust converting paints.

Paints don't usually convert, they attempt to seal the rust in so oxygen and moisture can't get to it and rust things further. POR15 gets a bad rap because people think they can just use it to paint over the rust but that approach rarely works.

As dlee6204 said, your best bet is to remove as much of the rust as you can. Wire wheels, brushes, whatever you can use to get in the spaces. I found this 3M rust/paint stripper to work really well. Ospho over that to convert anything you missed, then paint.

As others have said. You need to clean it to bare metal then epoxy primer. There are no miracle sealers for rust no matter what some products claim.

I do soap and water, solvent cleaner, abrasive of choice (mine is wire brush or green 3M bristle disc, more cleaning, acid etch, and coating. For really rusty metal I used Eastwood's rust encapsulating paint, and then epoxy primer.

For box sections and dead air spaces I use the Eastwood cavity paint.

I would add that in my process I would do several wet applications of the ospho while wire brushing between each application. The wire brushing brings the deeper rust out each time. Just be sure to have an old moving blanket or similar below to capture the dripping mess.

This is an interesting topic;
As the OP shows his surface rust, there have been a few answers of the remedy process with some variations. Thank you

The final steps being epoxy primer, then paint.

For the house garage type of repairs on a daily driver, what kind of epoxy primer and finishing paint would you recommend for these no so visible repairs?

Can something be done using good metal protecting products, without the need of a compressor and professional spray paint equipment? Read; brush and rattle can?

I am by no means a professional but in lieu of epoxy primer, I have used Dupli-color acid etch primer (rattle can army green) as a bare metal primer on all sorts of small places where you have bare metal showing. I have also brushed on POR-15 in non visable areas with "good enough" results. There are also excellent high build primers in rattle cans for final base coat prep. at your good automotive paint supply stores. Sand your primer down with 400 to 600 grit sand paper and spray your finish color. Whatever approach you decide to do keep in mind even a small compressor and an inexpensive HF spray gun and some practice will impress you with the results.

Tomorrow I will go to the local body shop supplies and see if they have Ospho or equivalent and also get some epoxy primer.

Thanks for all your replies,

IronHillRestoratios gets it right.

+1 Same approach here.

I spray interior body cavity’s with boat loads of Eastwood Internal Frame paint whenever I have access to it.

I'm a fan of SprayMax 2K Epoxy primer.

Comes in a rattle can that has two chambers. Before use, you puncture the 2nd chamber that dumps the catalyst into the main can cavity. Shake well, Spray. Real 2 stage epoxy from a can!

Pot life is about 3 days before the material in the can gets too thick to spray well. Pot life varies by temperature once mixed.

It is a bit pricy at about $20/can but slightly cheaper if you buy quantity.

https://www.amazon.com/Spray-MAX-Rapid-Prim...Y/dp/B00B3I2E8E

No compressor, no mess, no fuss, no need to carefully clean up spray guns to keep paint from hardening in them.

Wear a proper organic vapor respirator! They also have an Isocyanate free version p/n 3 680 031

You local paint store may also be able to mix color in 2K for small repair areas with the same type of 2 part can depending on your location.

I've used Eastwood's version of 2K epoxy in a rattle can. Might be a rebrand of what Phil linked but I've used it and it seems good.

Also, you can brush on epoxy primer. It just isn't as pretty as spray, but brushes on a protects just fine.

Although I have a compressor I went for the epoxy primer in a can. I will spray the floor pan at the same time so I dont waste the can. I removed the sound deadening to inspect the floor pan for rust.
Its good to know you can get the primer mixed with colour, I will ask for that next time.