Quick paint/rust question.

[Clodi]

Ysgyfarnog is still wearing her 'sailaway' coat of battleship grey. I know it looks pretty awful but I want to treat the odd surface rust spots on the roof etc & I have onboard a full tin of Hammerite red oxide and a similar Screwfix tin.

Question is, assuming I treat and paint the rust spots are there any undercoat paints that don't like going over Red Oxide when I come to paint it properly next year?

[Narrowboat Nimrod]

You could use the red oxide now but just make sure you bare metal all the red splodges next year prior to a repaint?

[Clodi]

Thanks, my plan i to get 3 coat on next year and try to top looking like a 'Crusty' boat.

[Sea Dog]

Once the steel is a bit cold to paint and the atmosphere a bit damp, my approach is to remove the worst of the rust and get a coat of Vactan on there. That has never failed to get me through to the next year without anything getting worse and it at least looks cared for once there's a black patch where the rust was. Being self priming, anything goes over the top of Vactan later on.

[peterboat]

^^^^^^^This is good advise, however if you get a warm sunny day you could paint with a fast drying paint, I have bought some two pack paint which dries fast and hard with a good finish ebay special not a bad price either

[Richard10002]

9 hours ago, Sea Dog said:

Once the steel is a bit cold to paint and the atmosphere a bit damp, my approach is to remove the worst of the rust and get a coat of Vactan on there. That has never failed to get me through to the next year without anything getting worse and it at least looks cared for once there's a black patch where the rust was. Being self priming, anything goes over the top of Vactan later on.

That's what I would do at this time of year.

 

Having said that, it would probably do little/no harm to leave the whole thing until March/April and start then. How much worse is the rust going to get between now and then? Not much IMHO... others may think different.

[Dr Bob]

11 hours ago, Richard10002 said:

That's what I would do at this time of year.

 

Having said that, it would probably do little/no harm to leave the whole thing until March/April and start then. How much worse is the rust going to get between now and then? Not much IMHO... others may think different.

I would agree with Richard and sea dog here.  ( Me...agree with Richard....??????)

I would avoid the 2 pack idea as that will need significant roughing up before over painting next year and it must be put on properly if you are going to paint over it. Too much faffing for me.

If you have rust spots now, a lot more of the area will have them by next spring so it will be a biggish job then. Richard's right that one option is just to leave it all till then. It not going to do it much harm.

The idea of vactan is good and easy to do. I have found getting hold of vactan difficult so have always used Fertan. Fertan works in a different way....I think it is 'thinner' so wets the rust better rather than sealing it...but it doesn't have its own primer.......  but that is not needed here as you will do that in the spring. I like the results of Fertan and if you are rubbing back the roof then this would be good. If you use Fertan or vactan, make sure the temp of the steel is high enough for what is required on the tin.

[Sea Dog]

1 hour ago, Dr Bob said:

The idea of vactan is good and easy to do. I have found getting hold of vactan difficult so have always used Fertan. Fertan works in a different way....I think it is 'thinner' so wets the rust better rather than sealing it...but it doesn't have its own primer.......  but that is not needed here as you will do that in the spring. 

EBay supplied my Vactan. The advantage over Fertan in this situation is that Vactan leaves a coating over the now treated rust, so you don't need to keep repeating the job or watch the rust steadily reappear. 

[Clodi]

Thank's everyone, I've got some fertan on board somewhere so I'll splodge it on  

[Dr Bob]

2 hours ago, Sea Dog said:

EBay supplied my Vactan. The advantage over Fertan in this situation is that Vactan leaves a coating over the now treated rust, so you don't need to keep repeating the job or watch the rust steadily reappear. 

I'm not really sure it is an advantage here. The Vactan will treat the rust and then seal it with its own primer as you said, but it is likely to be rubbed off again for the painting next year. I think the Fertan will get 'further into' the rust and so convert more of it but not have any protection....but should be ok for 4-5 months. It may then be easier to the prep. On balance both will do the job.

It is a bit of pain with Fertan having to wash it off the following day but it does seem to work very well. I did my engine hole with it this summer. I've read quite a few comparisons of Fertan vs Vactan but nothing good enough to say which is best at protection. Vactan is obviously the easiest to use as you can paint straight over it but you cant walk into a shop and buy it!