Gel Coat Stained... Help

[Captain Bill]

We were recently in a boat yard getting our saildrive repaired and while we were there the yard was grinding red filler off the boat next to us that was getting blisters repaired. Despite their use of a vacuum our boat was covered in dust. This was followed by a light rain. Our so called white gel coat is now a streaked light maroon. Not pretty. Of course the yard points out the "not responsible" clause in the paperwork I signed for the haul out. In any case after trying numerous products to remove the stain it looked like oxyclean was doing the job. We would put it on and we had nice white gel coat again. Sounds good, but the only problem is that the next day the stains are back. We've tried soft scrub, Clorox clean-up, Starbright cleaner/polish, West marine cleaner polish, etc. All of them seem to work to some extent, but the next day the color is back. We are at a complete loss on how to clean this stuff off. Please save the critcism about having a fresh coat of wax on the boat before going into the yard, that lesson's been learned. HELP!!!!!

[Ram]

Cap- How about some 3M Finesse-It II Glaze- this seems to make Gel coat like new , you need a buffer then wax- Good Luck!

[Cheechako]

That's tough... is your gel pretty pourous? Tried lacquer thinner?

[Overlord]

If you have the elbow grease , try 1200 water paper followed by buffing with Presta's strata t-cut. Your finish will be like the day she was launched. Use a proper polishing machine with a 3m wool pad at around 2000 to 2500 rpm

[minaret]

Yup, that is very common. All the yards around here mention it in their "best yard practices", and there are many disclaimers. We call it "the boatyard blues", as the staining is most often from sanding blue bottom paint, and once you get it you feel pretty "blue". Try buffing, then wet sanding and buffing if that doesn't work. If the dust mixed with water and got into a porous gelcoat, you are screwed, there is no way to totally remove it other than painting over it. Usually it will go away over time though. If you have porous gel you cant really blame the yard, it washes right off of non-porous gel. It's a manufacterer's default. This is one of the reasons we always tent heavily in our yard and never rely on a vacuum sander alone.

[capngeo]

No, No, and NO! just use an acidic cleaner like On and Off or even diluted muriatic on a rag (don’t spray as it does nasty things to aluminum). Wipe affected areas (insert standard precautions for eye, skin, and respiratory protection); rinse with water. Problem solved, no elbow grease required beyond wiping.

If the yard doesn’t know this VERY basic trick, they are not much of a yard. Back in the day, we used to sandblast bottoms out in the open... acid rinses were a standard procedure in annual commissioning and post bottom job on EVERY boat.

[minaret]

Originally Posted by capngeo

No, No, and NO! just use an acidic cleaner like On and Off or even diluted muriatic on a rag (don’t spray as it does nasty things to aluminum). Wipe affected areas (insert standard precautions for eye, skin, and respiratory protection); rinse with water. Problem solved, no elbow grease required beyond wiping.

If the yard doesn’t know this VERY basic trick, they are not much of a yard. Back in the day, we used to sandblast bottoms out in the open... acid rinses were a standard procedure in annual commissioning and post bottom job on EVERY boat.

I've always found that an acid wash will dull the gel a little and therefore needs to be followed up with buffing. So if the buffing alone will do the job just as well, why not leave out the nasty chemicals and hand scrubbing and go straight to a machine polish? We would never just acid wash a boat and send it out without polishing it first. We have tried it many times on boats with severe porosity issues, and it doesn't help. Nothing does, really. But I don't think that's the op's problem. I'd guess what the OP is seeing is caused by the yard workers sanding epoxy mixed with 407, which can cause staining. I've seen it cause severe and permanent staining when it was sanded before acheiving a full cure, thus leeching out all sorts of waxy amine blush and other chems when mixed with rainwater. His "streaked light maroon" sounds just like the effect caused by this. If this is what happened, I'd go back to the yard with it. Hard to prove though...

[HopCar]

I'm kinda with capngeo on this one. I'd try a mild acid first in a small area and see what happens. Maybe try Davis Fiberglass Stain Remover (FSR) first then if that doesn't work graduate to On and Off. If that doesn't work, go to the abrasives.

[capngeo]

Min: From my experience, I would suspect the streaking was caused by copper from the bottom paint around the blisters, not the epoxy filler. I’ve sanded a lot of filler and was always able to either blow it off or simply use a garden hose if it got wet. I’ve never seen an amine blush or stain from sanded resin.... wet uncured resin; yes I’d agree with you, BUT sanders and uncured resin don’t make much dust.. they sling goo!

Regardless you are 100% spot on about going back to the yard whatever their contract said. Unless they are the only yard for 100 miles, they will soon go out of business with that level of customer service.

ETA: Of course the acid will strip wax necessitating a wax job. (Hence the dulling noted by Minaret)

[cburger]

The yard's get out of jail free clause doesn't cover abject negligence. If the workers gave a **** the should of tarped your boat a reasonable expectaion.

Why should you bust your ass trying to repair their damage. Consult an attorney and have him take over the discussion with the yard owner, bet you'll get a different answer.

[David_Old_Jersey]

Maybe worth having a go at the neighbouring yacht's owner - after all it was him who instructed the yard........

Sorry, can't think of any solution.

[cburger]

This is all about negligence and damages. I don't think the adjacent boater instructed the yard not to take preventative measures to protect other boats while work was being performed.

[minaret]

Originally Posted by capngeo

Min: From my experience, I would suspect the streaking was caused by copper from the bottom paint around the blisters, not the epoxy filler. I’ve sanded a lot of filler and was always able to either blow it off or simply use a garden hose if it got wet. I’ve never seen an amine blush or stain from sanded resin.... wet uncured resin; yes I’d agree with you, BUT sanders and uncured resin don’t make much dust.. they sling goo!

Regardless you are 100% spot on about going back to the yard whatever their contract said. Unless they are the only yard for 100 miles, they will soon go out of business with that level of customer service.

ETA: Of course the acid will strip wax necessitating a wax job. (Hence the dulling noted by Minaret)

I've seen a great deal of stains from bottom paint dust, and it always stains the color of the bottom paint, not copper colored, ie blue paint makes blue stains, red paint makes red stains.So it is the pigment in the paint causing the stains, not copper. And generally when doing a blister repair all of the bottom paint has been removed first so you can find and repair all the blisters, though who knows how this was being done. So I doubt it was from the paint "around the blisters" as there shouldn't be any in a pro repair. How would you dry the hull properly with the paint still on? Personally when we do blister repairs we dont use any filler or fairing compound in the blisters at all, epoxy or otherwise, but that's us. Strictly fresh laminate glassed a little high and ground fair. I've seen loads of epoxy slicks that were sanded the next day after an application, even with fast hardener in cool damp weather that means the cure cycle is incomplete. It sands fine and makes plenty of dust, but the dust is still a little sticky and will cause stains, particularly when mixed with water. And while most solvent wipes will do nothing to gel, I find a muriatic acid wipe, or a 202 wipe, or any other acid based wipe will dull bare gelcoat with no wax on it, requiring you to polish it to restore the original gloss. So why not skip the nasty chems and just wet sand and polish it? It's usually much quicker anyway, no suiting up in gloves and respirator required. I do 800 grit DA film discs for big areas and the rest 800 wet by hand, then polish. Done in no time...

[minaret]

Originally Posted by cburger

The yard's get out of jail free clause doesn't cover abject negligence. If the workers gave a **** the should of tarped your boat a reasonable expectaion.

Why should you bust your ass trying to repair their damage. Consult an attorney and have him take over the discussion with the yard owner, bet you'll get a different answer.

It probably specifically does cover this particular event though. I know in our yard it is #1 on the best yard practices board in the yard, which clearly states all of our rules and is required in all US yards, we also hand a printed copy of BYP to clients when they haul, and a whole extra sheet which specifically addresses this issue titled "The Boatyard Blues". It's rarely a problem for us as we are very diligent tenters and the EPA is a constant presence, but the yard does take CYA measures. Boats with severe porosity do not do well at all in a dusty environment. I always recommend 20' wide "Sharkskin" film to our clients, it's easy to bag your whole boat with it and relatively cheap. We do so with all of our clients boats in yards other than our own.

[minaret]

If this particular staining was caused by bottom paint and not epoxy fairing compound dust, I've had much better results with bleach based soap mixes than almost anything else, even on porous gel. The bleach gets in to the pores and removes some of the color. I like Boat Zoap with bleach, do not use soft scrub with bleach, it's abrasive and will scratch your finish, although it's good for non-skid. Be careful making home recipes with soap and bleach, but that is what our cleaner crews swear by when dealing with bottom paint dust stains. I'm not sure what the latest magic bleach mix is, I could ask the cleaners though. They always have a mix of the hour. It's been years since I had to scrub a boat that is leaving, the joys of seniority....