Cleaning and repainting rusty bilges

[hopefulboaterlndn]

Hi again everyone!

Now the weather is starting to warm up me and my partner are going to have to face de-rusting, cleaning and repainting the bilges on our boat. Both our engine bilge and bilge at the front with water tank are very very rusty. There seems to have been a fresh water leak long ago and the rust left to 'grow'. The drains around the engine hatch need a clean out as rain water keeps getting down there. Also need some ventilation holes cut as there are none at all currently so the condensation is remarkably bad. Also our exhaust has a hole in it and now everything, EVERYTHING, is covered in a thick layer of soot. In our one inspection hole for the cabin bilge I can see orange rust - no flakes, and its damp (not wet).

In terms of dealing with this I was thinking of:

1. getting rid of water - wet vac

2.Throw more water down there and wash with soap to get rid of soot, wet vac again

3. remove rust with a wire brush

4. white spirit and cloths to remove grease

5. dry it out thoroughly

6. rust treatment

7. paint

Any recommendations to make this job easier? Any products people have found work well - Vactan? Do I need to be concerned about the cabin bilge? how much rust do I need to get off? everything is orange and covered in a thin layer of rust and there are flakes which can be removed with the wire brush but do I need do grind/sand it down or anything?

As always thank you in advance for your help!

 

Edit - I should point out that we are getting the exhaust fixed and part of this process will be removing the water so I don't have to ask someone to work with miserable wet feet

Edited March 24, 2017 by hopefulboaterlndn

[Iain_S]

I found Vactan not to be tremendously good when used in an engine bilge. I think it was because it wasn't warm enough (having a cool canal on the other side of the metal), and it wasn't really dry.

Would probably be OK if you could get some sort of heater to help it dry ...

[dor]

In the engine bilge, remove all loose rust and any oil.  Then use a liberal coat of Hammerite "Smoothrite".  Doesn't need a primer, dries quickly even if put on quite thickly and is resistant to oil once cured.  You can get it in white which makes it easier to see what is down there.

I've used it for years, and prefer it to bilge paint.

[WotEver]

33 minutes ago, dor said:

In the engine bilge, remove all loose rust and any oil.  Then use a liberal coat of Hammerite "Smoothrite".  Doesn't need a primer, dries quickly even if put on quite thickly and is resistant to oil once cured.  You can get it in white which makes it easier to see what is down there.

I've used it for years, and prefer it to bilge paint.

I used Vactan then Danboline but I think if I ever did it again I'd follow your advice with Smoothrite. 

[hopefulboaterlndn]

1 hour ago, WotEver said:

I used Vactan then Danboline but I think if I ever did it again I'd follow your advice with Smoothrite. 

 

1 hour ago, dor said:

In the engine bilge, remove all loose rust and any oil.  Then use a liberal coat of Hammerite "Smoothrite".  Doesn't need a primer, dries quickly even if put on quite thickly and is resistant to oil once cured.  You can get it in white which makes it easier to see what is down there.

I've used it for years, and prefer it to bilge paint.

Thanks a lot! i'll look into this

[Irob]

I had a sudden water ingress overnight from a leaky sterngland and it overflowed into the under engine section of the bilge, not a lot but enough. My bilge pump is not automatic and only serves the sterngland pocket. How to get the inch of water out? My neighbour clive had the brilliant suggestion to use baby pampers. I dutifully bought a pack of 10 for about £3, and promptly threw 4 under the engine. Within 30 minutes the bilge was all but dry. I fished out the heavily laden pampers and dropped them in the bin. I,ve got 6 left for another wet day, pun intended. Brilliant idea, thanks clive.

[Tony Brooks]

See warning in other thread.

If left soaking up for any length of time they tend to fall apart and dump the gel into the bilge. You were probably OK because you only left them down for half an hour.

[dmr]

Why do people like smoothrite? my experiences of it with old vehicles were generally negative, its very brittle and the does not stop the rust. I have also heard that its changed of late and is even worse.

Ultimate approach is to go back to bare metal then use a good primer but if the rust is deep this is not really viable unless you want to spend many hours with a needle gun.

Best option is to spend as much time as you can removing all loose rust. A wire cup brush in a drill could be used for the worse bits. Then paint with RED Owatrol primer. This does better than the venerable Bondaprimer if there is significant residual rust. It takes a fair time to dry. Then a coat or two of Danboline, I prefer the grey one.  I did this on the very back bilge which is often wet and after 8 years its still reasonably good.

................Dave

[hopefulboaterlndn]

In the end we scraped the rust off and then used a wire brush in a drill to go over it. We painted it with flag rust converter but I'm not sure it's worked properly. Most of it has dried black but there are yellow bits? Should I go over it again? A bit confused because I know it shouldn't be used below 10 degrees but it dried within a few hours, I'd expected it to have stayed wet if the temp was too low.