Removing rust stains from fiberglass!?

W

Wood Zeppelin

New member
Got a few small rust stains near buttons, roof rails, windlass(or maybe from the anchor chain) antenna bracket, through outside of hull.

Sometimes some lower grades of stainless rust a little in the salt, it seems (?)

I read about soaking the rust stains in a paste of baking soda and water for a bout an hour, then scrubbing. This seemed to work. The same article said to do a wipe with acetone and a rag. When I tried this, it was a disaster. It seemed to have smeared the rust color back into the gelcoat. More baking soda and scrubbing was needed to remove it. So, not sure about the acetone ..(?)

Any better suggestions for cleaning out rust (and other) stains?
 
Barkeeper's Friend works for me. A wet rag and some scrubbing usually does it.

I hadn't heard of the baking soda paste and wait method. Maybe I will try that next time. I think everything is cleaned up pretty good right now but tomorrow there will probably be something else!
 
This is the no-fail commercial product.

FSR - Fiberglass Stain Remover. You can find equivalent recipes on the web. The active ingredient is oxalic acid, so gloves are definitely recommended.

I would tend to shy away from anything abrasive, and I believe Barkeeper's Friend is an abrasive? Tell me if I am mistaken here.
 
Cheapest is to buy crystals of Oxalic Acid; Amazon and Walmart is $20 for 5#, a lifetime supply, just dissolve in water. Ace and True Value have it but more expensive.

I use a lot of Bar Keeper's friend content: feldspar, linear sodium dodecyl benzene sulfonate (DDBSA) and oxalic acid.

Even if some places say Bar keeper's friend is non abrasive, feldspar is a very mild abrasive.
Softer still is feldspar (Mohs 6), which is most famously used in the Bon Ami brand household cleaner. For the most delicate polishing and cleaning work, such as with jewelry and fine crafts,
Click to expand...

Acetone is a very bad idea--as you found out. It softens the gelcoat layers and the stain can become permeant. You need to polish it out.
 
Not sure of the exact proportions I used, but I did thicken it with wallpaper paste so it would stick when I put it on until I was ready to rinse it off. Make sure not to get it on your galvanized trailer (don't ask how I know, just take my word for it). Here is a recipe I just found that looks pretty much like the one I had before. it worked for me as well as FSR, great for removing rust stains:


Put 1 quart of hot tap water in a container (a bucket, for instance).

Measure 100 grams (about 4 ounces) of oxalic acid.

Stir the oxalic acid into the hot water.

Let the mixture cool and it's ready to use.

Optional: if you want it to "stick" better to a surface, you can add up to 10 tablespoons of powdered wallpaper paste.
 
Pat Anderson":3l6jylmy said:
This is the no-fail commercial product.

FSR - Fiberglass Stain Remover. You can find equivalent recipes on the web. The active ingredient is oxalic acid, so gloves are definitely recommended.

I would tend to shy away from anything abrasive, and I believe Barkeeper's Friend is an abrasive? Tell me if I am mistaken here.
Click to expand...

Any type of polish is abrasive or it won't do any thing :thup

Barkeepers is powdered oxalic acid & good stuff. Keep it off your concrete.
 
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