Corrosion Protection

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Gannet
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Corrosion Protection

Postby Gannet » Thu Feb 01, 2018 12:25 pm

There has been a lot of discussion on this form about corrosion problems especially of the cast iron cylinder blocks. The discussion has usually centred around how to remove/repair the corrosion, which has been the immediate problem. I have seen very little about how to prevent further corrosion taking place apart from running the engine in fresh water after a run in the salty stuff.
I think that putting away engines in unheated UK garages after use is a recipe for continual hidden corrosion. This may not be so relevant in some dry and hot environment in Australia for example. I can well imagine that in the humid UK climate the cylinder block will stay moist for some time and would produce ideal conditions for corrosion.

I put a dewatering fluid (eg WD40) into the block water jacket, which I am sure helps to a degree. However I am trying to obtain a fluid which gives much better longer term protection. Castrol Rustilo DWX32 and Millers Oils DW1744 are two possibilities. However these only seem available in 20 litre quantities, whereas 5 litre would be more than enough for half a lifetime. Additionally these fluids would be excellent for protecting spare/surplus parts from deterioration.

So, what do you use? Does anybody know of a source of small quantities of either of these two fluids or indeed good alternatives?

Jeremy

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Oyster 49
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Re: Corrosion Protection

Postby Oyster 49 » Thu Feb 01, 2018 12:41 pm

I'd agree with you Jeremy, a flush in fresh water and wash to remove all salt is must do maintenance for any engine run in salt. I try to run the engine dry for a couple of minutes also to help dry the waterways out.

All my older engines in store (Only a few now) are all given a quick spray with WD40 and a wipe over before running, and covered over with a dust sheet. This is far more than many seagulls get.

I'd agree with trying to get some WD40 into the waterways too. That's actually what it is designed for, a water repellent.

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Hugz
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Re: Corrosion Protection

Postby Hugz » Thu Feb 01, 2018 1:15 pm

If you seal the motor in a weatherproof bag with kitty litter it will absorb any moisture trapped within. Make sure your kitty litter contains silica. We need to find a source of sealable bags to accomodate our motors. This is the same material used in sachets in pill containers and the like.

You can put some in a pourous bag and keep in your car to stop the windscreen fogging up overnight or so l have been informed.

I keep all my motors inside in Oz and still have lost a few. Will the day come when they will be kept in a climate controlled room..... maybe in a century or two.

Gannet
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Re: Corrosion Protection

Postby Gannet » Thu Feb 01, 2018 5:57 pm

Adrian & Hugz - Thanks for your response. Yes, WD40 is reputedly the fortieth version of a water dispersant developed by the company - although I naively thought that it was developed exclusively for the Little Model Forty!

Interesting idea to keep them in a sealed bag, with low humidity inside the bag. Although difficult to use in conjunction with using the transom bracket. But worth thinking about. There is also the possibility of putting some vapour inhibitor inside the bag, which prevents corrosion by, I believe, a molecular layer given off from the inhibitor, which covers everything. I have some inhibitor produced by Vapor-Tek.

My main suggestion was to put some dewatering/corrosion protection fluid into the water jacket. At present I always squirt a lot of WD40 into the water jacket after flushing. But I want to use something which gives considerable longer and better protection such as Castrol Rustilo DWX32 or Millers DW1744. Does anybody know where I can purchase 5 litres of either? Or would some people like to share the 20 litre standard quantity?
Either will be very useful to have around to protect spares etc.

Jeremy

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Oyster 49
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Re: Corrosion Protection

Postby Oyster 49 » Thu Feb 01, 2018 7:59 pm

There is a Miller dewatering oil on eBay, expensive though.

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seagull101
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Re: Corrosion Protection

Postby seagull101 » Thu Feb 01, 2018 8:25 pm

I just flush by running for a few mins then use a quick squirt of wd40 up the tell tale, i also wipe the whole motor down with an oily rag (minus the carb and tank).I only have saltwater around me so have to do all this, or am i spoiling my motors?? :P

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NaughtyBits
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Re: Corrosion Protection

Postby NaughtyBits » Thu Feb 01, 2018 8:35 pm

Info from a website on restoring cast iron cylinders: filling the water jacket with any thick oil to prevent oxygen getting to the cast iron surface, once the cast iron is flushed & dried, is your best bet.

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Oyster 49
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Re: Corrosion Protection

Postby Oyster 49 » Thu Feb 01, 2018 9:12 pm

Yes, number one job is to get the salt away, followed by drying out the waterjacket if possible. I imagine any thin oil in there will be a great preservative!

Gannet
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Re: Corrosion Protection

Postby Gannet » Thu Feb 01, 2018 10:00 pm

I was speaking to OPIE this morning who informed me that they had 3 x5L of DW1782 available . It seems that they have possibly now put it on e bay. DW1782 is thinner than DW1744 and offers less corrosion protection.

Yes, drying out the water jacket is difficult. A dewatering oil is the best way to do that. And if it has good corrosion protection properties then that is ideal.

Certainly filling up with any old oil is a lot better than nothing, but it might not displace all the water. And using it again in possibly a river might not be a good idea if there is lots of oil still present and if there isn't, then you may not be getting any protection. DW1744 claims the surface thickness of the corrosion protection to be 5 microns - so not much oil to be flushed into the river.

I am surprised that this issue of corrosion protection of blocks has not received more attention, considering how much has been written about the problems of rusty and blocked up blocks and indeed cracked blocks due to excessive corrosion.

Jeremy

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Oyster 49
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Re: Corrosion Protection

Postby Oyster 49 » Thu Feb 01, 2018 11:05 pm

Yes, however the seagull often gets chucked in the corner of the shed or garage with good intentions and then left there!

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Re: Corrosion Protection

Postby headdownarseup » Thu Feb 01, 2018 11:41 pm

I've thought about the same problems with my 102's.

I do the usual flush through in fresh water as well, even though my motors never see any salty stuff. But there's always a first time for everything i suppose.

The rust problems seem only greater with the 102's cylinder as trying to get any decent access into the water jacket for cleaning/scraping any hard baked on rust is a pain at the best of times, so i've used an acid to at least try and dissolve the hard to reach bits until i feel the water jacket is as free as i can get it.This might take me several attempts to achieve what i would call a reasonable result and there's no more rusty flakes being washed out.

Now i've noticed that when i've run a few motors in my "test tank" at home there's a pretty good layer of gloopy oily residue floating on the surface of the water afterwards. As this residue is mostly oil and perhaps a little bit of unburned fuel i'm fairly sure that some of this oily mess has made its way back inside the water jacket that i've spent a long time trying to descale. This oily mess along with a liberal spraying of wd40 is what my flock gets by way of preventative measures. I try to resist the temptation of emptying this dirty water from the test tank in the belief that this "soup" actually does an ok job at coating some of the water jacket with a light covering of oily sludge. I'm even tempted to add some anti-freeze into the "soup" for good measure to see if there's any benefit to be had in the long term. For long term storage i try to block off any holes that would allow moist air getting back inside the cylinder or water jacket. A small wad of tissue paper soaked in oil usually does the trick for the tell tale pipe, and down below at the gearbox end i use some masking tape to cover the inlet holes or slots. Again a quick spray inside the holes before i cover with tape for good measure. I then turn the motor upside down and round and round to distribute the wd40 to where i can't get at with a spray can. For the carb and fuel system i make sure the fuel has been emptied out before hand and that the float bowl is empty too before i cover the carb/inlet cowling with a small plastic food bag and a cable tie with a little spray of wd inside the bag. I find that if i disconnect the fuel line from the float bowl and undo the throttle cover/slide everything gets covered over nicely with this food bag and cable tie, a final all over spray of all the external parts to the outboard with more wd40 and the whole lot gets covered over with a black bin bag or rubbish sack to keep the dust off till i'm ready to use the motor again. Some strategically placed holes in the bin bag to allow the bracket to poke through and the motor is put onto a rack (or not depending on available space :roll: ) for safekeeping till the next time.
A sticky label on the top of each bin bag tells me what's underneath the plastic at a glance.
After Hugo's suggestion i might try and find some absorbent granules and use them inside the bin bags, perhaps in a porous bag of some kind.
Every 3 months or so i like to turn the flywheels over by hand several times just to re-distribute any oil or wd40 i may have sprayed inside the cylinder bore. Just like a good cheddar cheese needs turning occasionally, i allow myself a small pleasure in turning a few flywheels from time to time and daydream of long summer days and calm waters :oops: ahem...

This might seem a little bit far fetched and probably not what most other 102's are likely to get in the way of some long lasting tlc but it's what i try to do whenever possible with all my seagulls big and small, and up till now i've had no problems as far as corrosion coming back in the water jacket or to any external parts that can suffer. Apart from a handful of very precious golden oldie gulls, all of my outboards are stored in a wooden shed at the bottom of the garden that now leaks quite a lot. :roll: This will soon get replaced by a shiny new metal shed as soon as i get a good dry weekend.

I do like the idea of using a protection fluid on spare parts till they get used on a rebuild. For the moment all my spare parts are sat in plastic ice cream tubs with tight fitting lids or bigger parts in various boxes in drawers. Maybe when Jeremy manages to acquire some of this fluid in smaller quantities i might follow suit, but for now wd40 works pretty good for me i have to say.
I even use wd40 on my ancient atco lawnmower. does wonders for it.
Each to their own i suppose.


Jon

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Re: Corrosion Protection

Postby Keith.P » Fri Feb 02, 2018 12:07 am

I use my motors in fresh water, so salt is not a problem, I just take a motor or two out for the day, in the process I stink the car out with fuel and once I get home, I just put them back in the shed, I only really use them in the summer, so they have a little time to dry out.
Not a problem for me really.

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Hugz
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Re: Corrosion Protection

Postby Hugz » Fri Feb 02, 2018 2:56 am

What is this stuff all about? Makes an impressive claim.

https://www.whitworths.com.au/desalt-ma ... remover-2l

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AusAnzani
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Re: Corrosion Protection

Postby AusAnzani » Sun Feb 04, 2018 11:50 pm

NaughtyBits wrote:Info from a website on restoring cast iron cylinders: filling the water jacket with any thick oil to prevent oxygen getting to the cast iron surface, once the cast iron is flushed & dried, is your best bet.


This is an old school method that shouldn't be discounted. I purchased a 1914 Evinrude RBM a while back that had been sitting in a shed in Tasmania, last used back in the 30's or 40's as advised by the seller. The crank case assembly and water jackets were filled with oil and sealed off before it was put away. Once drained, the benefits of the above-mentioned were clearly visible. Internally, it was like new.

Gannet
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Re: Corrosion Protection

Postby Gannet » Thu Feb 22, 2018 10:48 pm

Yes, there are a multitude of ways to prevent corrosion, especially within the cast iron water jacket. I think the key is to choose a method that one is going to adopt and actually do it. The method will of course depend on expected storage time and usage of the engine and ease of the process.
I have obtained some Millers Oils DW1744 dewatering oil and have been using that on some spare blocks and gears and in an FV engine which has just been run in the tub after a salt water run. I am fairly pleased with the process. Its a bit messy, compared to just squirting a bit of WD40 around, but I hope and expect that the corrosion protection will be much more effective.
The critical aspect will be not just thinking and talking about doing in, but to actually do it in a routine and regular manner.

Jeremy


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