Paint for cast iron gutters - Hammerite smooth?

[nothanks]

I've recently replaced the one 6m length of PVC gutter bodge on the house with cast iron to match everything else (a slightly tough job, single handed; where are the off-spring when you need them?) The new stuff was pre-painted and looks great, but it's reminded me how bad the rest of the guttering looks (in good condition, but bad paint and with leaking joints). The plan is to take it down in sections, wire brush, paint, re-fit with new bolts and seals, and to adjust the brackets to improve the falls. The question is what to paint it with. My first thought was inside and outside with Hammerite smooth, but I've read reviews saying that it flakes quickly and is a pain to apply ("not as good as it used to be" is a common comment). Other suggestions are to use bitumen paint inside and almost anything outside. Any recommendations from people who have relevant experience?

[Tricky Dicky]

I would be very wary of taking it down if badly corroded you may find yourself with a pile of bits. If it is still reasonably sound and not full of holes with pieces breaking off, I would paint it in situ, bitumen paint inside wire brushing treating the outside with a rust converting paint before applying a decent zinc based primer after which a decent undercoat and gloss to finish off. When Hammerite was still good I recall the smooth version was not recommended for exterior use, I don't know if that applies to the current version. Generally Hammerite in my opinion is not what it used to be.

Richard

[tabbypurr]

I'm told hammerite is now no better than ordinary gloss paint. Dulux do metal paints but IMLE they're nothing great. Bitumen is relatively good at covering all sorts of sins & cheap, long as you like black.

NT

[alan_m]

When I repaired some cast iron I used paint stripper, then wire wool, get down to bare metal. Then a rattle spray can of primer followed by a rattle spray can of white "industrial" paint from TS.

sell other colours)

[soup]

I am pretty sure part of the advertising jingle used to be

? Inside Smoothrite outside Hammerite Iron old Iron ?

I take it 'Smoothrite' is now called 'Hammerite smooth' or somesuch.

Most things with chemicals in them seem to follow the same path the chemical proportion has been so reduced (to follow H&S guidelines) that the product they are in is no longer so effective.

[Tim Watts]

Smooth hammerite has always been a bit flakey - though I once had good results baking a small piece in an oven.

The hammered finish seemed to stand up to anything, but some say it was prone to pinholing.

I agree with the above - a good quality zinc primer will go a long way to a good finish.

sorry - can't advise on modern metal paints - so much has changed and strangely I've not had the need to paint exterior metal for a long while.

[polygonum_on_google]

A while ago I needed to paint a metal framed A-sign for outdoor use. I used:

Zinsser All Coat Exterior Paint Black 1Ltr (Screwfix 8716G)

Was really nice to use - wash brushes in water. Quick drying.

Unfortunately, it is quite expensive and I don't really know how well it lasts in the longer term.

[Tim Watts]

Lateral idea - what about a good car underseal - maybe something like the Waxoyl range? Some people swore by giving that a coat of Waxoyl liquid once every few years to keep it soft.

[Brian Gaff]

I seem to recall that some of the ingredients that used to be in it have had to be replaced by others for health reasons, and I strongly suspect this is why its now not what it was.

Who remembers red oxide being replaced by Engenamel?

Yes on cast iron. make sure its good before taking it down. also due to its weight the hardware that holds it up and what its screwed into need also to be in good condition. I have to say that my gutter is now all plastic. OK you say, the company who removed it thought it was a good little earner for the scrap, but not really when they were taking it down it was immediately obvious that parts of it were paper thin and whole bits could simply be broken off with bare hands. Tin worm and age and stress had taken its toll. It looked good but was forever leaking at joints which was why I had it done. Brian

[nothanks]

Thanks for all the replies. AFAIK the gutters are mechanically good (especially considering they're

80 years old) so I'll continue with the plan to take them all down, paint and refit. The "Zinsser All Coat" looks like the way to go. I should get the appropriate tuit once the real Spring arrives and will try to remember to report back.

[nothanks]

Thanks. It gets good reviews.

[Dave Liquorice]

Does bitumen paint ever truely dry/set? Inside a gutter you don't want anything "sticky" to collect the general atmospheric fall out, dust, grist from slates/tiles, leaves, twigs etc.

Painted our cast iron gutters with Hammerite a good few years back. Still look good (from ground level). It's fussy stuff, which is why I think many people have trouble with it.

If you miss the fairly narrow (4 or 6? hr) recoat time you need need to wait the two weeks. You just need to splap it on and not brush it out too much. The inevitable tiny bubbles in a thin coat will tend to remain and form pin holes in the coating. Bubbles aren't quite such a problem with a thicker, less brushed out coat they rise and surface tension pops 'em before the paint has cured too much within limits. But the second coat within the recoat time is fairly critical to filling any bubble pin holes that are present.

[tabbypurr]

nt

yes, a couple or 3 days in winter. Then over further days it gets harder. Very durable stuff.

NT

[Jim K..]

Matt black...

[Jim K..]

Worth knowing?