how can i remove rust marks from fibreglass?

Sam_Steele

Sam_Steele

Well-Known Member
Joined
22 Apr 2003
Messages
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Location
Winchfield, Hampshire
www.circumnavigation-uki.co.uk
just had some work done on the boat which involved grinding off a metal bar.... i thought i cleaned up all the dust.... clearly not well enough as my lovely fibreglass now has rust marks. ( not happy is an understatement). i have just spend a few hours rewashing the entire boat to remove any more bits of metal dust. should i do any thing else to prevent it getting worse and how do i remove the rust marks. thanks in advance
 
rust removal from fibreglass

Sam_Steele said:
just had some work done on the boat which involved grinding off a metal bar.... i thought i cleaned up all the dust.... clearly not well enough as my lovely fibreglass now has rust marks. ( not happy is an understatement). i have just spend a few hours rewashing the entire boat to remove any more bits of metal dust. should i do any thing else to prevent it getting worse and how do i remove the rust marks. thanks in advance
Click to expand...


Mix a good cupfull ofOxalic Acid crystals to a quarter bucket of water, paint over liberally wait 20mins, rinse well, all done...... simple.Works on stainless too.
 
Gelcoat cleaner

Use Y10 can be bought here or other chandlers :-http://www.theyachtshop.co.uk/items/paint~maintenance-and-electrical/cleaning-materials/boat-cleaning-products/y10-fibreglass-stain-remover-gel-h04348-detail.htm
 
Sam_Steele said:
just had some work done on the boat which involved grinding off a metal bar.... i thought i cleaned up all the dust.... clearly not well enough as my lovely fibreglass now has rust marks. ( not happy is an understatement). i have just spend a few hours rewashing the entire boat to remove any more bits of metal dust. should i do any thing else to prevent it getting worse and how do i remove the rust marks. thanks in advance
Click to expand...

Stain Devil for rust.
Cheapest and easiest to get hold of.
Tesco.
£2.
 
You will find that you will have to keep cleaning this area with your oxalic acid over a period of time until the rust particles have all rusted away, the hot particles from the grinding melt into the gel coat, and thats why they keep coming back.

next time you do some grinding make sure you cover the area around the grinding to minimise the cleaning up.
 
There is an abrasive polish sold in most chanders comes in 3 grades soft, med, and hard, is a normal polish but for stubborn stains or scratches, chips, etc give it a hard rub and it will come out and leaves no marks just a perfect surface.

SP
 
Just a thought. You say the bar was cut using a grinder? The offending rust spots, they wouldn't be where the hot sparks have melted into the gel goat would they?

:eek:
 
"sweep” the area with a magnet including the route taken overboard by water used to wash down. As recommended above, Y10. Comes in a gel form so application can be localized.
 
Each small mark is a bt of metal, and if washing hasnt got it off you gotta scrape them off individually with the tip of a stanley knife blade. I sawed through an anchor shackle on a windy day and three years later i have just about got rid of all the rust flecks on the deck.
 
Sam_Steele said:
just had some work done on the boat which involved grinding off a metal bar.... i thought i cleaned up all the dust.... clearly not well enough as my lovely fibreglass now has rust marks. ( not happy is an understatement). i have just spend a few hours rewashing the entire boat to remove any more bits of metal dust. should i do any thing else to prevent it getting worse and how do i remove the rust marks. thanks in advance
Click to expand...

Cillit-Bang! is quite effective to remove rust marks. Spray and leave for five minutes then rinse with plenty of water. Easier to find than oxalic acid. Cillit Bang! contains acid, therefore do not overdo it because as every acid it will make the gelcoat go opaque.
 
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