Internal hull rust advice

[DBA Forum (B) - Roelf Aukema]

Hi,
I am in the process of buying a Dutch barge. I have had a surveyors in-water report done. The report mentions that there is some rust visible on the inside of the hull and that only a small portion of the hull could be seen due to it being inaccessible. What could be seen was minor rust.

After talking to the surveyor, he said that it was just a matter of cutting access hatches in the floor and treating the rust with oil. Can anybody enlighten me on the process and reality of treating hull rust? Do you really have to pull up the whole floor and remove rust and treat and paint? Or is it normal to "oil it" every so often? What are the processes and components for oiling the inside hull?

Any advice would be appreciated and soon if possible as I need to make a decision on the purchase. I really don't want a project boat but am OK to refurbish, paint and modify. The out of water pre purchase survey will be done if we proceed to the next step and this will reveal hull thickness and therefore give some further indication of the hulls condition.

Thanks for your help.

[DBA Forum (B) - Richard Cooper]

Well, the best thing is to pull up the lot, shotblast and paint it but the more sensible thing is to get access to as much as possible, get rid of as much scale as you can and in my opinion brush waxoyl or similar onto the bottom. others will perhaps recommend oil, new oil may be better as old engine oil is acidic.You will not really know the thickness of the hull until the next step, it could all be fine. If it is ok then you can extend its life by epoxy paint and waxoyl, in the end any treatment is better than neglect. That's what I would do but there are a lot of variables in these things

[DBA Forum (B) - Roelf Aukema]

Thanks Richard. I will take onboard your advice. The more the merrier. Cheers.

[DBA Forum (B) - Balliol Fowden]

The reason most Dutch barges are still with us is that traditionally they were "oiled," "greased" or "waxed" out in all hidden areas, e.g. under the hold sole. The three terms mean the same thing. I used to call it "grease" until somebody took me at my word and used Castrol XM! The Dutch product, "anti-roestvet" or lierally "anti-rust fat" is a wax-like petroleum based product that has to be warmed to put it on but seems to last almost forever. It sets to a dryish, waxy texture unlke Castrol XM! A thinner version is available but neither pours without heating. Waxoyl is a poorer quality lighter weight version, but still much better than paint. I re-treated many areas of our bilges last winter that I had last done with Waxoyl nearly 30 years before and the rusting was absolutely minimal.

Internal corrosion is a serious problem and can sound the death knell for riveted barges. Dutch barges have the simple design fault that all the limber holes (drains) through the frames are along the centre line, so water can and will collect between the frames if the ship is not floating dead level. This corrosion rots the outer areas of the bottom where the water puddles, and can set up corrosion and scaling between the plating and the bottom frame flanges, which really is serious since it causes rivet failure, sometimes on an industrial basis.

So preservationis essential and that is where a lot of older conversions fall down. Don't buy a barge with extensive bottom frame rivet problems. Your surveyor should know ways of spotting that problem without getting inside.

To preserve, in order of preference:

1. Clean out all areas and treat with a thick layer of anti-roestvet. Paste it on warm with a scraper.

2. If you really cannot get to areas (and it is worth trying hard!) then drill (hole-saw) funnel-size holes at discrete points and pour in a thin oil. I use hydraulic oil since it seems to be clean, low flammability and non-corrosive. Old sump oil is not a good idea. The oil will make its way gradually aft, coating the same area where water will lodge, and it will seep behind the frames. this does give you a slightly oily bilge of course but in areas such as the hold, which should be discrete (i.e. have water tight bulkheads) then a bilge pump with bilge oil filter will suffice since you should not be using it regularly. Clearly the intention is not to "flood" the bilge with oil. Over 30 years I have simply "topped-up" whenever the thought has occurred (perhaps every five years) with anoth
er few jugs of oil poured in to holes near the front of the hold. It does seem to get aft, but the more access points the merrier if you can find discrete spots to cut them.

Balliol.

[DBA Forum (B) - Tim Hackett]

Peter Voerman suggested spindle oil to me for this purpose. Castrol offer it. Very thin and "creepy" but I think hydraulic oil may be cheaper.
Tim

[DBA Forum (B) - Roelf Aukema]

Wow, what great advice! Thanks to you both. Nothing beats years of practical learning by those who have actually done it.

The DBA forum really is superb!

Roelf.

[DBA Forum (B) - Frank Kordbarlag]

My favorite shipyard (Rosemeier in Minden) uses an American anti-corrosion oil and they swear by it. I forgot the name but can ask them if you like.

Frank

[DBA Forum (B) - Tim Hackett]

It would be useful Frank if its no trouble. Its not "Navy Steel" is it?

Tim

[DBA Forum (B) - Frank Kordbarlag]

no, it´s not navy steel, but I ask them tomorrow and post it. I need to speak to them tomorrow anyway.

Frank

[DBA Forum (B) - Tim Hackett]

Ta!

Tim

Tim and Jo Hackett

mv Maria of Zaandam

'I distrust camels, and anyone else who can go a week without a drink.'

On 22 Jul 2014 22:06, 'DBA Forum (B) - Frank Kordbarlag' <dbabarges-pvYRptiajiAdnm+***@public.gmane.org> wrote:


no, it´s not navy steel, but I ask them tomorrow and post it. I need to speak to them tomorrow anyway.



Frank