Rust Stains?

[Chris Reinke]

I recently purchased a "project boat" to work on for fun. I rebuilt the engine at the end of last season, replaced the teak over the winter, and I am now concentrating on the hull. The hull is very sound with only cosmetic issues. The boat was very neglected by the previous owner and they had no idea what they were doing....don't we all install our accessories using steel sheetrock screws into the fiberglass? The best were the steel thru-hull bolts below the water line holding a swim ladder on the stern (rusting bolts with no caulking) which caused the boat to partially sink prior to my purchasing her.

One of my biggest pain points are the various rust stains the screws have left all over the cockpit and stern. Does anyone have a suggestion for removing the stains and filling the holes? I was considering the 3M 4200 or 5200, but welcome other alternatives.

[Bill Goldsmith]

Chris,

4200 would be a good choice to temporarily plug the hole(s) to prevent further water ingress, especially if you think you might want to use the hole again for accessories installed properly. If you simply want to seal up the hole(s) you probably want to fill them with epoxy and then matching gelcoat.

Cleaning rust stains on older chalky gelcoat can be challenging. Try a very mild abrasive like Bon Ami, or even a very light wet sanding with 400 then 600 paper.

What kind of boat is it?

[tmsc]

You may want to try CLR. You can usually find it in grocery stores or Wal Mart. If that does not work ON-OFF bottom cleaner or SnoBowl toilet cleaner. SnoBowl is cheaper. Warning NOT TIDY BOWL which will stain. (Had somebody do that one time) Both SnoBowl and ON-OFF are acid based products that will take off a lot of things. The stuff will take brown water stains off gelcoat and will help remove dried barnacles. Just be careful with what it gets on and the fumes. Apply it to the gelcoat when it is dry and let it work for a little while. Keep a water hose at the ready and rinse really well. If this doesn't work then move to rubbing and/or polishing compound. After that, sanding and/or painting is about it. As far as holes are concerned, I like to use white Marine-Tex for small holes, chips and gouges. You can sand it down in incremental steps to 1500 - 2000 grit then finish it with 3M Finesse-It and wax to a new gelcoat shine. If you are going to paint skip the waxing step. Good luck.

[Gary H]

Last year, I left my boat uncovered under a maple tree. Leaves and the flowers from the tree fell on it and mixed with rain left stains. I tried everything to no avail except for bleach which worked perfectly.

[Mike]

Chris,

Try a product called Wink. It comes in a brown colored can and is available in hardware stores. It will remove rust from almost anything. I've even left old rusty SS screws and a little wink in a zip lock bag overnight. Next day brand new shiney SS hardware. Even the fumes remove rust.

Best,
Mike

[bhartley]

For those wanting to search online, the product referred to Mike is actually Whink. I was introduced to it by my grandmother many years ago. Works like a charm every time.

Mine is in a brown plastic bottle with a white squirty cap. You should be able to find it in the cleaning supply section at the grocery store.

Bly

[tartansailor]

Boil water,
Put on eye protection and rubber gloves.
Dissolve as much acid as boling water will take.
Rub stains with saturated scotch brite.

If the stains are not severe and you do not wish to go the above route, use "Bar Keepers Friend" (from most super markets),
which also contains oxalic acid.

Dick

[Dalton]

Is the ingredient all right. It gets rid of most organic stains. I use the stuff from Davis called "FSR". It's a gel and so you use a disposable brush and paint it on and rinse it off. Wear gloves and eye protection! The brown on the water line just goes away. Any harder stuff takes several applications. It will even melt the remains of barnacles away on the prop. This takes more than just a few light applications though, and a maroon Scotch Brite.

GD