Cement wash coating for steel protection

[cyclops]

Would a construction company who does any type of metal construction in salt or fresh water have a Engineer that would know? Pure Portland Cement and water is very very water proof. Look at bridge piers.

[MikeJohns]

Ferro cement yacht hulls include Pozzolan to make the plaster less permeable.

siliceous pozzolans react with the non-cementitious calcium hydroxide in the hydrated cement paste to produce (highly cementitous) calcium silicate hydrates, yielding higher strength and dramatically reduced permeability.

A "pozzolan" is defined as "a siliceous or siliceous and aluminous material which in itself possesses little or no cementing property, but will in a finely divided form and in the presence of moisture chemically react with calcium hydroxide at ordinary temperatures to form compounds possessing cementitious properties


Cementitious and pozzolanic materials

High-calcium fly ash (class C)
HCFA is the residue collected from the smokestacks of coal-fired power plants generally using lignite and subbituminous coals. Class C fly ashes are in themselves mildly cementitious, and have been combined with lime or even calcium carbonate soils to produce moderately strong concretes.

Ground Granulated Blast Furnace Slag
GGBFS is the ground residue from iron smelters, and is also mildly cementitious in itself, but hugely pozzolanic in combination with water and cement.

2. Highly active pozzolans

Condensed Silica Fume
CSF is a waste product of the silicon metal industry, and is a super-fine powder of almost pure amorphous silica. Though difficult (and expensive) to handle, transport, and mix, it has become the chosen favorite for very high-strength concretes (such as for high rise buildings), often in combination with both cement and fly ash.

3. Natural sources
Pozzolans are present on earth's surface such as diatomaceous earth, volcanic ash, opaline shale, pumicite, and tuff. These materials require further processing such as calcining, grinding, drying, etc

______________

So we want a chemical that turns the calcium hydroxide into a calcium silicate hydrate.

[safewalrus]

As a (old?) Merchant Seaman we used to coat our fresh water tanks annually with a cement 'wash' made up of Portland cement - NO secret Ingedient! mixed with water to a thick mess, 'bout the consistency of porridge and applied it using soft brooms. Let it dry and washed out the tanks by filling once then refilling for use. Sweet as you'd ever get - not like modern composites which seem to fail frequently! Or maybe it was because we were not so sophisticated in those days!

[D'ARTOIS]

I have asked my sister to look in my files that are in France.....Although she breeds horses and know bl***y nothing about boats exept to get seasick in no time...........

[Riley]

Aloha, Sorry to bud into your forum, but it is important for me to let the world know that my late father, Victor Riley, invented Tapecrete. Through devious business practice, his graduate student's family continues to profit from his genius. They took away the money, but they can't take away my father's legacy. Please spread the word that Victor Riley is the true inventor of Tapecrete. Victor, a mensa member and civil engineer, was an avid boater and rower, as are all of his children. Born into poverty, he worked in mines in northern Canada to put himself through university and eventually graduated from Cambridge University with a PhD as an Athlone Fellow. He used Tapecrete for everything. In the early days, the UofT's faculty thought he was nuts when he built a racing canoe out of what they thought was concrete. I loved hearing my dad tell the story of how he won the race with his "concrete canoe". He even built us a 2-story playhouse out of the magical stuff. Please help spread the word that Victor Riley invented Tapecrete.
Thanks heaps!

[JimCooper]

Alas another wronged man. Sorry to hear it.

Perhaps you can remember what he had in the shed then we can reproduce this admix ourselves and shaft the thieves and pirates who stole the recipe !

Dartois

did your wee sister ever come up with that paprer you had the recipe on ? I want to use a brew on my brothers boat.

Jim

[D'ARTOIS]

After so many time, I have found the recipe. Mike, please consider that this recipe dates back to 1936 when it was published for the first time. later on, in a more recent publication 1953, the recipe was repeated, unchanged.

Use as an method of application to/on an already existing coating:
Nafta......................100dl
Aluminium Stearate.... 10dl
Icevinegar........0,3 - 0,5dl

The nafta should be pre-heated till 80 deg. Celsius and than one dissolves the alu stearate in the hot nafta.
After the stearate has been dissolved well, one ad the Ice vinegar or Ice acid to the solution under well stirring.
One gets a transparent viscous solution.

For direct application to the unfinished cement, one ads the aluminium stearate direct to the dry cement, about 100 till 200 gram per bag of cement.

The first recipe is for coating the already applicated cement.
You may also use ammonium stearate for the same purpose.

Hopefully, this brings you somewhere.

Regs
Brien

[MarkC]

Nafta is parafin wax or kerosene? Nafta is an American term?

Icevinegar is ?????

Ahhhhh - the terminology of the 1930's

All we need now is some 'Paris Green'!

Is the Aluminium Stearate safe to hold water?

Just curious.

[JimCooper]

Originally Posted by D'ARTOIS

After so many time, I have found the recipe.
...................
For direct application to the unfinished cement, one ads the aluminium stearate direct to the dry cement, about 100 till 200 gram per bag of cement.

D'Artois

I have an immediate application for this when I've finished my welding!
Would like a bit more help please.

You add 200grams to What size bags of cement? 40kg ?

Then mix with washed beach sand say 3 sand to one of cement with the Aluminium Stearate added to the cement.

Does this sound about right for filling in the bottom of my bilges ??

Thanks
Jim

[D'ARTOIS]

Yes, the recipe says so - between 100 and 200 gram per bag of 40 kgs dry cement without the sand.

Yes, one to three mixture is ok; the cement wash is also an excellent rust-preventer. In the old days it was applied to the bilges of the commercial barges that travelled the Dutch waterways. It was also used as a way of internal ballast. You can treat it afterwards with part no one of the recipe.

Good Luck!

[jglassman]

Originally Posted by D'ARTOIS

After so many time, I have found the recipe. Mike, please consider that this recipe dates back to 1936 when it was published for the first time. later on, in a more recent publication 1953, the recipe was repeated, unchanged.

Use as an method of application to/on an already existing coating:
Nafta......................100dl
Aluminium Stearate.... 10dl
Icevinegar........0,3 - 0,5dl

The nafta should be pre-heated till 80 deg. Celsius and than one dissolves the alu stearate in the hot nafta.
After the stearate has been dissolved well, one ad the Ice vinegar or Ice acid to the solution under well stirring.
One gets a transparent viscous solution.

For direct application to the unfinished cement, one ads the aluminium stearate direct to the dry cement, about 100 till 200 gram per bag of cement.

The first recipe is for coating the already applicated cement.
You may also use ammonium stearate for the same purpose.

Hopefully, this brings you somewhere.

Regs
Brien

A little help: what are the units/mix ratios mentioned above? Is dl a deciliter? Is this per 100lb bag of cement?

[Brent Swain]

All embeded material we made for embeding in cement in the steel fabricating industry specified that the steel be allowed to rust slightly, to ensure better adhesion of the cement.
Brent

[LyndonJ]

Why does Bruce Roberts claim that cement makes a steel boat corrode ? He says this in his book on metal boat building. Yet Ive seen ships cement washed that sat on the sea bed for years and the steel was as good as new under the cement.

[MikeJohns]

I think this is based on the problem that large blocks of 'stiff' poured concrete particulalry in high slamming areas tend to separate from the 'elastic' steel. Water gets trapped in the interface. A little rust then pushes the steel further from the concrete. Anchor lockers in particular suffer.

[druid]

We manufacture and coat large diameter steel pipes. For drinking water supply systems, the cement internal lining is specified in accordance with AWWA C205. Allowable cement type and sand/cement ratio is mentioned therein.

On the other hand, solvent free epoxies suitable for drinking water are much more effective for lining of steel surfaces.