Bar keeper's friend leaves a deposit....

[ChasB]

No, not what it sounds like.

Following some advice in another thread, I've been using the poor man's StarBright to clean the hull and remove rust stains. It's much the same stuff, oxalic acid, with a bit of citric acid thrown in but also something that leaves a white deposit that's a bit difficult to remove.

Not an issue on a white gelcoat hull, but on tarps and windows it's a bit unsightly.

Anybody else had this problem and know how to remove this easily?

Thanks!

 

[thinwater]

The problem is that the person on the other thread didn't know what he was talking about.

Barkeeper's friend does NOT contain oxalic acid. It contains surfactant (soap) and a mild abrasive. On tarps, the residue is the fine abrasive (feldspar). It should wash out, but it can be very stubborn. On windows, you probably scratched the plastic and will need to buff them out, in stages, with appropriate compounds (you could Google headlight lens restoration) and wax them; that will be a bit of work. NEVER use Barkeepers friend on a window. It's a scouring product, like very fine sandpaper, and must be used with extreme discretion. Much better to understand the chemistry of the stain and use the correct product.

This is why they teach chemistry in school.

Learn to read MSDSs and only use products off-label if you really know the chemistry. All of life is chemistry.

 

[Skylark]

Google suggests ingredients as follows:-


The Bar Keepers Friend ingredients in the Cleanser & Polish powder and their Cookware Cleanser & Polish are:

Feldspar*
Linear Sodium Dodecyl Benzene Sulfonate (DDBSA)
Oxalic Acid


I’ve used it, based upon reading these threads, to clean surface rusting around shrouds and bottle screws and it’s worked a treat. I’ve not noticed a residual white deposit.


https://www.barkeepersfriend.com/wp-content/uploads/2014/12/SDS_BKF_Cleanser_Polish_6-12-15.pdf

 

[Spyro]

I've used the powdered version of bar keepers friend on stainless with great results but for rust stains on grp it didnt work nearly as well as straight oxalic acid dissolved in water.

 

[RichardS]

The Bar Keepers Friend ingredients in the Cleanser & Polish powder and their Cookware Cleanser & Polish are:

Feldspar
Linear Sodium Dodecyl Benzene Sulfonate (DDBSA)
Oxalic Acid

Oooops ... that's torn it for us Chemists.

Richard

 

[Skylark]

Oooops ... that's torn it for us Alchemists.

Richard

Fixed it for you. :encouragement:

 

[Scubadoo]

I found vistal the best cleaner for removing Rust stains and all sorts of marks, no connection just a happy customer.

https://www.vistalcleaningproducts.co.uk/boat_cleaning.htm

 

[thinwater]

Google suggests ingredients as follows:-


The Bar Keepers Friend ingredients in the Cleanser & Polish powder and their Cookware Cleanser & Polish are:

Feldspar*
Linear Sodium Dodecyl Benzene Sulfonate (DDBSA)
Oxalic Acid


I’ve used it, based upon reading these threads, to clean surface rusting around shrouds and bottle screws and it’s worked a treat. I’ve not noticed a residual white deposit.


https://www.barkeepersfriend.com/wp-content/uploads/2014/12/SDS_BKF_Cleanser_Polish_6-12-15.pdf

I stand corrected. I went off memory, which was 50% correct and 50% wrong. And this makes more sense.

It's going to be good for rusty stainless, no question. Acceptable for gelcoat, though you are sanding off some material in the process. But not for windows or canvas because of the feldspar. In fact, when compounding flexible vinyl windows (which doesn't really work well), it is know thing that you mask the canvas to avoid getting compound on it.

 

[Neeves]

Thinwater - your Bar Keeper's Friend and that available in the UK do not necessarily have the same chemistry.

I would be surprised if any abrasive cleaner only contained Feldspar. It would be possible to only contain one mineral - but I suspect there will be others present. Not that it makes any difference, anything softer (like acrylic or gelcoat) will be abraded. It look fine for cleaning stainless or glass (in a bar).

Jonathan

 

[ChasB]

Hi. Sorry for delay. Router died.

I haven't used this on perspex windows - I'm more cautious than that. And being cautious didn't rub it in but applied it diluted with a paint roller and with a little wallpaper paste to stop it running down surfaces. My hull is now the proverbial whiter than white!

The window was a black hatch window.

The white deposit is slowly coming off in the rain, but at this rate will take forever! There's likely a suitable solvent, but I wanted to check here to see what would most likely work and not damage the boat. I was thinking of pure diluted oxalic acid..?

 

[ScillyPuffin]

Assuming the white residue is predominately deposited Sodium Dodecyl Benzene Sulfonate (SDS) then you may want to try warm water. SDS has low solubility in water and alcohols, but this increases above 25C. Oxalic acid should dissolve off easily in an excess of water and the Feldspar would have a low reactivity at these conditions and should also wash off eventually. I haven't checked the full list of ingredients, so there may be other interactions.
A secondary source might be the wallpaper paste - I'm assuming this was water based, else it might be causing you issues.

 

[VicS]

Hi. Sorry for delay. Router died.

I haven't used this on perspex windows - I'm more cautious than that. And being cautious didn't rub it in but applied it diluted with a paint roller and with a little wallpaper paste to stop it running down surfaces. My hull is now the proverbial whiter than white!

The window was a black hatch window.

The white deposit is slowly coming off in the rain, but at this rate will take forever! There's likely a suitable solvent, but I wanted to check here to see what would most likely work and not damage the boat. I was thinking of pure diluted oxalic acid..?

I would try washing with something like a car shampoo or maybe a caravan cleaner

Be very cautious about solvents on plastic glazing

 

[ChasB]

The warm water tip worked. And a bit of gentle rubbing.