Just in the process of giving Blue Swell a good clean and am going to use oxalic acid to brighten the topside gelcoat as has gone slightly yellow.
What i need to know is the best thing to mix acid in and how many parts acid to water do i need to use, i was thinking about using a hand spray bottle and sponge to apply but how long do i need to leave on for? Obviously safety googles, gloves and plenty of water to wash down are a must.
This summer an idiot was using a grinder to repair the railing of the catwalk in our marina. Red hot iron particles burned into Tommie's cabin roof paint and within a week the whole roof was covered with rusty brown shine.
I used oxalic acid 1:10 for 5 min. and all the iron particles are gone, but also the paint became dull, so I had to polish and wax her.
How are you going? I always hydrochloric acid 1:5. Only do small areas at a time and don't let it dry. I didn't know that you could use oxalic acid. Always thought that it was for timber. Have you got an electric buffing machine? You really get a much better result and also easier on the arms. (If not Hitachi SAT/180 is the one I have for light work. It has 2 speeds). In combination with a "super buff" (again from 3M) buffing pad (double sided). For buffing I use a 3M gelcoat buffing compound and then a 3M wax. I've tried everything but the 3M seems the best.
Haven't had a chance to take out our boat since coming home, but trying it for a few days over xmas/new year.
I now dont know what to use, i thought Harold it was you that said oxalic acid ? so im now confused which to use i will look into hydrochloric as well. I do have an electric polisher so will be using that eventually but still cutting back the gelcoat, now letting finger nails grow back, the only trouble with shaped mouldings lol! A few bits of gel are thin in places and will have to have minor repair but progressing well but slowly!.
Will look into 3M products but have G3 cutting compound and using Autoglym silcon resin polish and happy so far with finish.
keep you posted, but would like to know which acid to use.
Geoff............
-- Edited by Blue Swell on Wednesday 24th of November 2010 05:55:52 PM
Just done a google search and it seems Hydrochloric (muratic) acid is Brick and mortar cleaner hadnt realised this!. Please correct me if im wrong. I used brick cleaner to clean props and stern gear with good results in the past.
Hi Geoff and all, I had some idiot grind metal all over my car once. It rained shortly after and when it stopped I watched in horror as my blue car went rusty brown and felt like sandpaper. The company concerned paid to have it treated with, I believe an oxhalic bath, where they paste this stuff on and cover it with tissue paper to let it work then wash it off and polish. Whatever it was, it worked! Try talking to a car bodyshop specialist as they would know. Hope this helps and good luck Geoff. Regards. Dave.
i will look into hydrochloric as well.
