Rewhitening Yellowed Gelcoat

[GordMay]

Originally Posted by Maine Sail

... I make a 14" tall drip skirt out of heavy duty sheet plastic that gets taped to the waterline and hangs free at the bottom edge. Any acid run off rolls down the drip skirt and drips off the bottom edge, not along the hull.

✌ Indeed !

[oceaneddy]

Anything with phosphoric acid in it will remove the stain.Limeaway, LRC, Lysol toilet bowl cleaner.Somtimes you can find full strength sold by the gallon.Metal shops sometimes have it to clean rust prior to painting.Dont get it on any metal you want to keep shiny.Or as stated your boats bottom paint.

[Beenjammin]

OK, tried the paste trick on the weekend. 50/50 success. The oxalic crystals work well but the paste bit didnt work - this time.

I Mixed the flour/sugar paste up at home Wednesday night, then took the bucket to the marina and on the Saturday morning tried to mix the crystals in, first dissolving the crystals in water. This was two days after I mixed the paste and by this time the paste had become jelly-like and didn't want to mix with the dissolved crystals. I ended up just brushing the dissolved crystals without the paste onto the deck - and it worked really well! I let it sit for about 10 mins then used a cheap pressure washer to clean it off. Didn't effect the aliminium toerails or fittings. (sorry, no pics. Will remember next time).

Sunday afternoon I went to throw out the bucket of goop and saw it had kind of re-set. I kept it and will try it next weekend.

BTW, also tried another trick I read about using brasso to polish perspex windows - works great! The only thing is I used a power polisher and got some on the hull. The white gelcoat around the windows now shines beautifully but has taken on a rich pinky-bronze sheen, almost pearlescent. Could be an interesting and unique effect if I did the entire boat but they only sell brasso in those little 8oz bottles so the cost to do a 43 footer would be prohibitive. I guess acetone will take off the brasso stains.....:b

[Beenjammin]

My boat cleaning saga continues....

I used Drifter (Phosphoric Acid) to clean my topsides before polishing. Next morning I noticed it the acid had left a black stain on the white non-slip textured gelcoat where I had left the broom I was applying it with.

I didn't have a chance to try to clean it up. I'm back at the boat in a few days...any suggestions how to remove the black stain? Will more phosphoric acid remove it? Or will I need something stronger?

Thanks!

[oceaneddy]

If you use Phosphoric acid full strength you should rinse anything it comes in contact with not more than an hour or so after. your broom may have some metal part that has reacted with the acid and bled out and stained the deck.Reapply acid?Dont know,sounds like you may have a Cat In the Hat situation.Good luck.

[Johnathon123]

In Australia you can get a product called easy off bam (not sure anywhere else). You need the gel not the spray. Cleans the yellow right off