Mill Scale on 1982 Bayrunner by Westcoaster

[minuteman62-64]

Came across a post on one of the other sites that makes me think some stuff on the exterior of my hull may be the result of mill scale not being removed during the manufacturing process. Boat is 1982 Bayrunner, by Westcoaster. On trailer almost all of it's life. Sat dormant from 1992 till 2008. I'll post photo of the stuff of concern as soon as my camera battery recharges.

For now, anybody know if the Westcoaster (or was it Valco?) folks took care of the mill scale issue during the manufacturing process?

[minuteman62-64]

OK, here's a picture of the outside of the bow portion of the hull, above the water line.

[kmorin]

min'man, I'm always sniveling about mill scale and corrosion so I'll offer some thoughts at the risk of Jettywolf calling me the Mill Scale National Socialist (gnat-zee).

The film is the result of milling release agent and sales imaging (its shiny!) and is often left by even major mfg's since its 'looks good' to the ill informed; before sale. The film is #1 Porous and retains water vapor; #2 Allows the initiation of a from of crevice corrosion termed loosely, poultice corrosion and #3 has a galvanic difference to the underlying alloy even if that last is small.

So you can get rid of this with mechanical or chemical means; or both.

And to answer your original question, this could be mill scale as it looks OR it may be some spray on lacquer failed over time and UV deterioration resulting in the same surface corrosion due to thin films of water turned to acid kept in close proximity to the underlying oxygen starved metal- shown in your photo.

Jettywolf has a really nice set of threads, here, on his cleanup of his Pacific, I think it had Nyalac at the build (?) and was just spotty for color, but his threads will help you decide how to move ahead to recover your skiff. There are other threads here dealing with some more detail so the Search function would be your best tool.

Chaps does this work all the time as part of his boat services "bidness" so there are lots of sources to refer to here- if you want to explore this further(?) It really doesn't matter what the builder did; it's done. As I see it, you need to get some Zep or a buffer and give this skiff some attention

Cheers,
Kevin Morin

[minuteman62-64]

I've now read a whole bunch of posts on mill scale. Based on above comment, whether it's mill scale or some type of factory applied coating, it should come off. Appears two ways to go - mechanical removal and acid etching. Lots of posts on acid etching, not much on mechanical removal. I'm not too keen on the acid etching, so leaning to mechanical.

Photo below shows same hull section as previous photo, but with part buffed with one of those reddish brown 3M discs chucked in my drill motor. If I could get a similar disc for my angle grinder or my buffer I could do 2-3 square feet/day and have it done in a week or two.

Am I on the right track? Is the buffed condition shown in the photo what I should be striving for?

[gandrfab]

For me, to see it and change light angles makes a world of difference.
Looks good.

[Chaps]

I think you might try sanding it first with an orbital sander using progressively finer grades of paper and then go to your buffing process of choice

[minuteman62-64]

I think you might try sanding it first with an orbital sander using progressively finer grades of paper and then go to your buffing process of choice

I'm thinking it is not an emergency so can deal with it this Winter. In the meantime I'll be looking at a variety of media - for the balance between rapid removal and not too aggressive on the hull surface. Open to other suggestions from you guys with the experience in this area.

On a related note, visited the Shelter Island launch ramp yesterday p.m. and talked to owners of 2 mid-19990's Bayrunners and one early 1980's Gregor. Asked them if they'd done anything about mill scale like etching/buffing/etc. Got blank stares in response. One guy stated that, w/regard to etching/buffing/cleaning/painting/etc., he'd bought his Bayrunner so he ".... wouldn't have to worry about all that s**t."

None of the boats had the "flowering" quite to the extent that mine does. After a lot of reading on here, I've concluded that, regardless of cause, it is not good to leave this "flowering" since it will hold water/salt and cause continued problems (buffing a small area I did notice slight pitting under the areas where the "flowers" were located). So, I'm planning on removing it. But, I'm wondering if maybe the Gregor and Bayrunner folks might actually have removed mill scale after all and the "flowering" on mine is a result of something going on during the almost 20 years it sat dormant on rotting, saturated bunks.

[gandrfab]

What about all the spots you can't get to?

[minuteman62-64]

What about all the spots you can't get to?

The boat/motor package only weighs about 700# so it is easy to raise up off the bunks. If I pull the bunks out (which I plan to do in any event to install those "glide sticks") I can access the all parts of the sides and the entire bottom. The inside is painted and the paint is still solid after 30+ years, so, I have to assume the Westcoaster folks did it right.

That leaves the transom. I've already conceded that I'll have to re-skin the transom some time down the road - it has pinholes as a result of leaching from the unsealed plywood backing it up (at least that's what my readings indicate). So, I'll either pull the motor and buff the transom now or wait till I need to have it re-skinned.

Don't think there's any other area(s) that I won't be able to get to.

[solarkid1a]

OK, here's a picture of the outside of the bow portion of the hull, above the water line.

I have an 18 ft 1982 "Valco" Bayrunner with the same exact millscale and flowering problems.....

I'd like to share my story and experience:

I got this boat used because the previous owner passed away and his daughter eventually sold it.
Unfortunately, the family left it sitting in their driveway for over 5 years. There was a 20 to 30 lb brick of lead sitting in the boat in direct contact with the aluminum flooring that had worn Zolotone paint. Also, when I tore out all of the rotted flooring and pressure washed all the clogged drainage channels, numerous small lead fishing weights came out.

I do not know if the lead was the cause but it was definitely suspect.

I also found corrosion problems in several areas at the base of the transom where the floor seam joins.
They have since been fixed and I can comment on that later if you desire.

Basically the deeper I delved into the boat, the more problems I found. But, it was dirt cheap!

A really nice guy at Klamath who's name I forgot recommended a 3 step Sharkhide treatment.
1. Acid
2. Buff, buff, buff
3. Sharkhide sealant.

In addition to installing a zink, I buffed and buffed and buffed. I found a terry cloth buffing pad spinning at low rmp and a decent amount of pressure worked the best.
I'm talking 50 to 60 hours of buffing!

Great learning experience but I'll never buff like that again.

After all of that, I only got to use the boat 3 times before I had major outboard problems and my first baby was born (last year). The boat has been in my driveway ever since.

I don't feel like the boat has spent enough time in saltwater since all of the corrosion/millscale/flowering treatment for me to confidently say that its all been fixed.

However, I can say that it is definitely in much better condition than when I got it.

"I think it works" but the buffing process is exhausting and this was really my first time buffing something like this. I'm sure there are others on this forum that have experience and know how that could have saved me hours of torture.

I learned a ton but will never do it again.

Overall, I worked on the boat for over a year instead of going fishing. (This was a full overhaul)

I love the boat and will eventually replace the motor and one day be able to say it was all worth it.

Good luck but my advice is to make a decision: Do you want to fix a boat or do you want to go fishing? If you have a full time job, you don't get to do both.

[Chaps]

Great first post solarkid, welcome to the forum!

[Gypseas]

Good luck but my advice is to make a decision: Do you want to fix a boat or do you want to go fishing? If you have a full time job, you don't get to do both.

Or do both AND go fishing with one your buddies

cheers

[kmorin]

Everyone will decide how to clean up the corrosion found on these boats as the method best fits the tools and facilities at hand. My remarks here, are to explore what might be done to find a service to etch a skiff that are not necessarily marine services.

One thing to be considered, if you live in the States is the potential for a commercial firm to do the etching. Zep-a-lume is pretty strong stuff and as we've found at least in Florida (Jettywolf's reports on trying to buy Zep in his market) it's a controlled substance. But Zep Chemicals Co. makes this stuff all the time for a clientele other than welded aluminum boats. I think the tanker truck service centers use this solution to etch/clean/prep tankers trailers; so it's possible that a small skiff could be etched by a truck tank trailer service company?

It can't hurt to explore this possibility?

Next, remark; the design of welded boats is somewhat different from their welded and riveted cousins. The latter boats have nooks and crannies where a buffer cannot reach, in fact a wire brush probably won't reach either? (not that every single welded plate boat is free of such areas) So etching seems like the best way to get the most cleaning especially in areas hard to reach with tools?

If you use acid as weak as household vinegar, which some commercial products are, then the number of times of coating in order to fully clean (etch) the metal will be much higher than if you could use a concentrate like Zep-a-Lume (mixture of sulfuric, phosphoric, and hydrofluoric acids I think?) then the etching cleaning action will be able to act faster and more thoroughly in the deeper folds, laps and other tight places where potentially damaging corrosion cells reside.

Rinsing the acid off using a pressure washer highly dilutes it as its washed off, (of course only if you're wearing a HAZmat suit) so the waste is not a hazardous material. But the stronger acid's actions clean much more completely when applied and that could include cleaning inside the various tight places where mechanical tools might not reach.

So, while buffing can help large open areas of a boat to recover the base metal to a healthy oxidized state, most buffers are circular and therefore leave many gaps in overall coverage that can be reached by spraying acid over the entire boat. Strong enough acid, applied by a truck service company could be the most cost effective way to clean up the corrosion shown int he photos above.

I'm not sure if Chaps wants to remark about this idea? but it seems he could perform a similar specialized service for someone in his area (Puget Sound) with these boats in this condition- handling the concentrated acid solution and then properly rinsing a skiff perhaps hung keel up in his work bay?

Chaps have you had people come to you to get a 'white metal etch' on an entire boat of these types of skiffs? What are your experiences with the different acid etch products in regard getting clean of 'flowers'?

just a thought or two about using different acid cleaning products to help recover the underlying metal in this type of skiff.

Cheers,
Kevin Morin

[goatram]

My son had his Wedding on the first Weekend in Aug. My friend Bob offered his house and yard for the Wedding. He also likes to cook hence his user name BBQ Bob on BD. What he wanted was his boat polished up. My son had a great wedding reception. The food was great as was the Venue. Bob got his boat polished up. He had a lot of the little flowers around the stern area. The place that few wash down after fishing.

The boat is still in my shop out of the rain. His winter mods are almost done as well. AP, Garmin MFD, Fuel Flow, NMEA 2000 engine cable, new lights, 100 hr inspection along a good cleaning is some of the work he is doing. He is still waiting on the Engine Cable to arrive for him to install.

[Chaps]

I have not done much bare alloy restoration (deflowering?) up to this point as I tend to stay busy enough keeping up with bottom paint work but its a need that I'd like to develop some solutions for. There are a few people around that do straight up polishing like what John is showing in his post above and there is a lot of resource for that in the truck tank detailing biz as mentioned by Kevin. I think they are initially using acids to descale and remove the hard oxide layer in order to make the polishing process faster and easier. On a boat I'd think that once the mirror shine is on there and the base metal is no longer hindered by mill scale or clear coatings that the surface would likely oxidize evenly and take on a nice light gray that would look good for the duration and no longer get the corrosion spots.

However, I'm an abrasive blasting nut because that's the tool that I use to do the majority of the prep work on the bottom jobs that flow through my shop, even when I'm doing glass boats. I can't remember the last time I prepped a boat with a sander. Anyway, as the saying goes "if your favorite tool is a hammer, everything starts looking like a nail" applies to me in spades and I've been experimentally blasting alloy parts with various types of polishing grade blast media in an attempt to come up with a non-chemical method of quickly stripping corrosion, scale, dock rash and oxidation from the metal while simultaneously leaving the surface smooth, clean and ready to go back into service. Not shiny like a mirror mind you, I'm trying for a look that's best described as a "silvery glow" that is basically bright but not reflective, easy to clean and won't get oxidation splotch as it weathers.

So I've tried a variety of processes along these lines on what Kevin I think calls "coupons" (samples) and the plan is to move on to a bigger canvas this winter a.k.a. my boat which will be a particular challenge because it is so rough and grimy. I'll keep ya'll posted.

[SolarKid]

I just went to the Sharkhide Website: http://www.sharkhide.com/acinfo.html and pulled up the MSDS for their acid treatment.
It was a concentrated mix of hydroflouric acid and sulfuric acid.

When I used it, it seemed to work well. The directions were to place it in a plastic spray bottle and dilute with water as needed, etc...

There were however some "drainage channels" on the inside of the boat that I could not access and thus, did not treat.

Anyways, I think for me, it was more a matter of buffing and polishing and not having enough experience. I've done a bit of research on Youtube and found some buffing methods and tools that likely could have saved me hours.

I also wanted to mention that just last year I noticed at a boat show that the seam at the back of the more basic Klamaths provides a place for hidden water to accumulate. As many know, the drain plug just can't be flush with the bottom. Its about 3/8 inch high so even if you store a boat in a sloped driveway, it will not fully drain. I think their higher end models are welded the entire length of the seam line at the base of the transom.

After thoroughly treated those areas with acid, I then filled it all with epoxy. Time will tell on that repair?!?!

I live close to the ocean and salt fog is a regular occurence. My driveway is sloped. If we have a foggy night, the condensation from salt fog leaves water below the transom "at the stern seam".

[minuteman62-64]

[/quote]


I have an 18 ft 1982 "Valco" Bayrunner with the same exact millscale and flowering problems.....

I got this boat used because the previous owner passed away and his daughter eventually sold it.
Unfortunately, the family left it sitting in their driveway for over 5 years. There was a 20 to 30 lb brick of lead sitting in the boat in direct contact with the aluminum flooring that had worn Zolotone paint. Also, when I tore out all of the rotted flooring and pressure washed all the clogged drainage channels, numerous small lead fishing weights came out.

I also found corrosion problems in several areas at the base of the transom where the floor seam joins.
They have since been fixed and I can comment on that later if you desire.


Good luck but my advice is to make a decision: Do you want to fix a boat or do you want to go fishing? If you have a full time job, you don't get to do both.[/quote]

As was the case with yours, my boat sat, covered, in my side yard - although for about 20 years. Had some good rot on the aft plywood components, including the transom. I wonder if the simple sitting around, with a lot of water/moisture inside, is a contributor to the flowering. As I mentioned, the other boats I observed, some same age as mine, didn't have as much.

Since my boat is now 30+ years old, and the pitting under the "flowers" is very shallow, I don't regard it as an emergency. I plan to think about solutions, stage the solutions (maybe buffing) over time, and, keep fishing in the meantime. Since I'm now 74, I figure if I do nothing the boat will still outlast me. I would like to be able to turn it over to my Grandkids some day, however :)

[minuteman62-64]

Slowly moving along. I've pulled the trailer bunks and installed "Glide Strips" on top to minimize moisture being trapped against the hull along the bunks.

While the bunks are off I've been buffing the aluminum in that area, removing (I hope) the mill scale, which is also removing the "flowers" that have cropped up in places. Where the "flowers" are removed, small pits remain. Do I have to dig down into those pits to remove mill scale? Or did the corrosion and flowering already remove it?

I've ordered a rotary steel brush that will let me dig down into these pits - but don't want to waste time if not necessary.

[welder]

That rotating steel brush is a STAINLESS STEEL one isn't it?

[minuteman62-64]

That rotating steel brush is a STAINLESS STEEL one isn't it?

Absolutely (I've learned a few things on here :) ).

[minuteman62-64]

Almost done buffing the bottom hull where the bunks sit. I'll be able to do the remainder after the boat is back sitting on the bunks.

Actually wasn't too bad under the bunks - just the areas immediately forward and aft of the bunks were severely pitted.

See photo - before on right and after on left. You can see the very light pitting where the "flowers" were buffed away.

Do I need to do anything more on the buffed areas? I really don't want a painted hull and I'm not particularly interested in dosing myself and surrounding area with phosphoric acid or similar.