Uh oh! Is this corrosion?

[goatram]

After two months under the Carport I devoluped flowers as well. I will clean them up after I am done in the shop. This past Summer had no issues at all. Left it alone for a two months under cover and stuff happens

[wetwhopper]

Hi John. Been loving your build thread. Your ship (I mean boat) is going to be awesome. Tried texting you a few times but I think I have an old number. Yah, that mill scale is a pain in the arse! Misery loves company. Luckily I have two huge hatches, one forward and one aft to get down in the and etch the hull and bottom of the floor.

Chaps and Kevin, thanks for the tip. Maybe this won't be as big of a deal as I thought. Just have to remember to take the Sharkhide off the hull first!

Kevin, you just gave me an idea my other thought would be taking the boat to Koffler (who built my boat) and negotiate a deal with him as they paint boats "in-house" I'm pretty sure.

[gandrfab]

OH no , I have used about a gallon of lacquer thinner a year for the last 13 years to clean marks and hand prints of my pipe before I weld it.

Guess when I do have organ failure I can blame it on the lacquer, and not the drinking.

[kmorin]

Left it alone for a two months under cover and stuff happens

Yes John, that's the case, the cover created a Washington Weather 'dew generator' so the mill scale could have plenty of fresh condensate/water to get the corrosion going and keep those cells working in a short time! At least it seems like a pattern to me?

cheers,
Kevin Morin
Kenai, AK

[wetwhopper]

Kevin, good news. Got off the phone with Joe at Koffler boats and asked him if he could acid etch the boat. He said he could do it at what I think is a fair price. I'll drop it off early one morning soon and pick it up at the end of the day.

Thanks for putting up with me! I think I'll still be able to afford downriggers. Lol.

[Rendog]

Hi guys, well this is the second time I have written this post as I am not the most computer savvy person and ended up deleting it by accident. So this one is going to be a bit more to the point. Since my last post it appears lots has happened, that will happen when a guy does shift work!

Wetwhopper it seems you have found a solution for your boat and really how much better can it get if the manufacture is going to help you out! If you do happen to consider a second option, I have found a place in Vancouver Canada which will sandblast the affected areas and if you wish, paint it. It sounds like they do this to a number of aluminum boats as they seemed to be quite familiar with the procedure. For me the problem is Vancouver is 7 to 8 hours away.

Like Wetwhopper I too have contacted the manufacturer and I am waiting for him to review the photos that I sent. The problem for me with taking the boat back is it's a 13 hour drive each way, plus our Canadian dollar is no longer very good when compared to the US dollar. Thankfully I bought the boat last year, it would have cost me $9000 more in just the exchange rate if I bought it today!!

Another solution is to use Aluma Brite acid wash and then polish. I spoke with a fellow that has a Thunder Jet with some unwanted corrosion. He used the Aluma Brite acid wash, diluted it down and then applied it to the affected areas. He said it immediately brightened the boat but then it turned white, most likely from the corrosion of the acid. With panic in his eye, thinking he destroyed his boat, he polished it with Blue Magic polish and now has a mirror finish. Not something I think most of us want. But maybe a more diluted solution of acid wash and then a clean of some sort and finally a rub with scotch brite pads to help provide a more uniform look.

Lastly, I bought a coarse and a fine scotch brite pad and tried them on the hull below the water line so no one would see it should I have made a mistake. I quickly learned that the finer pad was the one to use and rubbed the hull until the corrosion was gone, "stars" or "flowers" plus the natural oxidization. It didn't take long to do the small surface but doing the entire hull from the chine down will require a bit of work. I also tried it on the reverse chine on the rear pod. This area turned out exceptionably good and looks like new or better to me! The problem I see with the hull area is keeping a uniform look.

A question I have for Mr. Morin if he is reading this, will rubbing the aluminum with the scotch brite pads remove the mill scaling and allow the aluminum to oxidize naturally in a uniform fashion without using the acid wash? By the way I have now read a number of your welding posts on other sites and found them interesting.

The first two photos are the hull and the next three are the reverse chine on the pod.

John

[wetwhopper]

Hi rendog,

Glad you finally got some time off from work. I had a buddy who did something similar to what your doing to an old Klamath with good results for the short term (was sprucing up the boat to sell) but not sure about long-term results. Sorry I'm not more help. I will say it looks awesome. This is my second aluminum boat in four years and I never really had the need to fix anything on the Alumaweld.

[goatram]

A friends North river polished in my shop. About 40 hrs total spent.

My son Jamie is doing the work here. We had his wedding at BBQ Bob's house

[bfetcho]

Rendog,

It looks like you've got the right idea. I posted a thread in the middle of last year called Corrosion on Hewescraft Ocean Pro 220 and it was about the same "flowering" issue that you have. I actually acid etched my boat and then put two layers of shark hide on after the boat dried to begin with. After about 6 months of use I noticed the same thing you are looking at on your boat which was strange as I had not seen or noticed this before. After learning from members on this site, I quickly removed the sharkhide with laquer thinner (which took a lot of elbow grease) and decided to acid etch the boat again. After a couple more times of acid etching at full strength (no dilution) I realized that this was not going to get rid of it. I too went for the abrasives 400, 600, then 800, then 1000, then 1500. After I felt that I had got it all, I then found a more powerful aluminum cleaner (Acid etch) and cleaned the boat again. Since then I have not noticed any recurrence of the corrosion and I am not going to re apply the sharkhide as the metal is doing a great job of protecting itself. Note: The acid etching is very easy to do with a little patience and a great deal of safety equipment in place (full respirator, rubber boots, tyvex chem suit, double rubber gloves, etc.)

I have just acid etched the inside of the hull after pulling my floorboards and discovering some corrosion issues due to sprayed in foam that stays wet. This is another issue I need to figure out how to deal with.

Glad to hear your manufacturer is willing to do this at their facility, good luck!