Cleaning and painting galvanised steel

[mo]

Hi

To cut along story short I need to build a structure in my garden which is built out of scaffolding. I have bought some poles and connectors. They were second hand so need to be cleaned and painted.

A cuple of questions

With regards to cleaning I am planning on sanding them down and then using sugar soap to wipe them down. I have had good results with sugar soap for cleaning some iron weights. Will suagr soap help or is there something better? Its just to get the dust and stuff off really.

connectors are pretty filthy, some of them are just covered in dirt. I will probably leave them in a solution of sugar soap and then wire brush them. Any other ideas?

Secondly I need to paint the scaolld poles.

I have used Hammerite for another job recently and whilst it does the job the stuff is far too expensive for the quantities I will need,

Therefore I plan on using anjormal metal primer and probably using gloss or silk paint.

The structure will be left outside in all weather but not abuse so I need paint that can stand weather but not necessarily 'use'. I understand as long as I prime is properly the paint should just go straight on.

Anyone know the cheapest way to paint galvanised steel? Hammerite or using a seperate paint primer method?

If I can get them shiny and clean and silver I may not even need to paint but that looks unlikely.

[Nightjar]

I would hire a grit blaster. They are ideal for complex shapes and a lot faster than sanding. You won't need to soak first either.

Colin Bignell

[Paul - xxx]

+1

Excellent bits of kit, very, very effective. ;)

[Bill]

In message , mo writes

I can't remember what we actually used, but when we painted the then new hot dip galvanised fittings on the boat, we used a suitable, for-galvanised primer followed by the same marine gloss paint that we used on the rest of the boat ( I put my hand up at an auction and got many cans of unknown colour paint - turned out to be all the same decent colour for, I think, a fiver). That was 25 years ago. We have only repainted where chains have run over it. It is now a bit matt.

[Tabby]

I wouldnt want to sand the zinc coating.

NT

[Nightjar]

On 07/06/2011 20:21, Tabby wrote: ...

The main problems is that it would be extremely tedious to do. Zinc dust, however, has no known long term effects on health and the short term ones are readily avoided by wearing appropriate protective gear.

Colin Bignell

[Tim Lamb]

Hmm.. arc welding zinc coated items gives me a headache as does dust from rust removal jobs.

regards

[mo]

"Nightjar wrote in news: [e-mail]:

I dont want to pay out to hire a blaster

Will a good pressure washer do?

I can imagine it doing a job on the poles - connectors might be fiddly though.

[Tabby]

It can however ruin the galvanised coating, specifically when its electroplated.

NT

[dennis]

That wouldn't matter though.. zinc corrodes in preference to the steel and that's how it protects the steel. If its plated there isn't enough to protect the steel (well not for as long as the paint will).

[Tim Lamb]

I doubt I do more than 5 hours welding in a year and never in a confined space.

regards

[Bill]

In message , "dennis@home" writes

I'd be quite interested to learn how most scaffolding is galvanised. I was always told that hot-dip galvanising was the only "proper " galvanising, and to avoid anything "spray galvanised". I assume this referred to flame spray galvanising, where molten zinc is sprayed onto the steel.

Is galvanising sometimes done by electroplating? I'd have thought the sizes involved would have made the spray method the easiest.

Some of the scaffolding poles beside my shed show some yellow discolouration, which I assume is very light rust.

[Nightjar]

I've never used one, so I have no idea what they are capable of.

Colin Bignell

[Nightjar]

That is a short term effect, with no known long term consequences. You really need a fume mask when welding and a good dust mask when abrading. Dust proof goggles and gloves are a good idea too, as it can cause temporary irritation.

Colin Bignell

[The Other Mike]

That's the way UK spec steel scaffold poles are protected, inside and out.