Richard10002 Posted March 13, 2020 Report Share Posted March 13, 2020 8 minutes ago, blackrose said: The clue is in the words "surface tolerant" . Prep should be good but it doesn't have to be perfect and what I've done is 10 times better than using vactan. I made the mistake of using that crap in my engine room and with the moisture the rust was back a year later. I used "that crap" in my previously badly rusted engine room a couple of years ago, and it's still looking fine :) Link to comment Share on other sites More sharing options...
Welby1965 Posted March 13, 2020 Author Report Share Posted March 13, 2020 I am a welder fabricator by trade and rust has always been a problem but i have never seen rust like i had in the bilge of my boat. I started scraping away and it came up in literally large pieces the size a dustpan about 1/2 a mm thick. Dont think it has ever been treated since it was built 20 years ago. So that's why i tried to get it back to solid steel and used a rust converter now rather than wait but i regret it now because it looks like it will take weeks to dry ? Link to comment Share on other sites More sharing options...
blackrose Posted March 13, 2020 Report Share Posted March 13, 2020 (edited) 2 hours ago, Dr Bob said: I think you will be ok with the Fertan but it does need to be washed off with water. It will have reacted ok in 48 hrs. The problem then is that you will really struggle to get the wet surface dry enough to paint, and if you do then the temp is too low to paint properly as you are always likely to be below the dew point uless the temp warms up a bit. I doubt if Vactan will work any better as it is too cold for coating below 5°C. Which perhaps is one of the reasons it didn't work on my engine room floor. It was summer but I suspect the water temp was at or below 5C. 22 minutes ago, Richard10002 said: I used "that crap" in my previously badly rusted engine room a couple of years ago, and it's still looking fine Try using vactan and a single pack primer/topcoats in an area with standing water and see how long it lasts. If it worked in your case then that's great and that's all you need, but it's simply not the best system and that's why it's not used by most professional painters. By the way, that wasn't originally my description of vactan. Early on in the project while we were working on prepping the bilges of Steatley we were visited by the head of technical of the Cutty Sark project. In my canal boat naiievity I suggested using vactan and he said "Don't use that crap." Streatley Edited March 13, 2020 by blackrose 1 Link to comment Share on other sites More sharing options...
Old Son Posted March 13, 2020 Report Share Posted March 13, 2020 (edited) I had a lot of rust develop on the underside of my roof rails. I chipped off the worst and applied Vactan. It is still rust free after 3 years. It is out in the open and suffers the abuse of the weather. I'm quite happy with Vactan. Edited March 13, 2020 by Old Son Link to comment Share on other sites More sharing options...
blackrose Posted March 13, 2020 Report Share Posted March 13, 2020 Good, carry on with it then. I wouldn't use it again. Link to comment Share on other sites More sharing options...
MtB Posted March 13, 2020 Report Share Posted March 13, 2020 10 minutes ago, blackrose said: Good, carry on with it then. I wouldn't use it again. Really? I haven't noticed you mention this before! 2 Link to comment Share on other sites More sharing options...
blackrose Posted March 13, 2020 Report Share Posted March 13, 2020 3 minutes ago, Mike the Boilerman said: Really? I haven't noticed you mention this before! Didn't you notice me mention it? Well in that case just for you Mike, in summary: I think vactan is crap and wouldn't use it Link to comment Share on other sites More sharing options...
Murflynn Posted March 13, 2020 Report Share Posted March 13, 2020 7 hours ago, Chewbacka said: But it’s rusty in the corners.......... never mind the corners - on my screen the quality of that photo is so good that I can see brown patches in the dips all over the place. Fact is - there is little point in trying to do any painting other than emergency patching at this time of year. Vactan will at least dry and provide a sealing primer that will keep the gremlins away until the temperature and humidity have improved so that a proper job can be done. Link to comment Share on other sites More sharing options...
blackrose Posted March 13, 2020 Report Share Posted March 13, 2020 (edited) 28 minutes ago, Murflynn said: never mind the corners - on my screen the quality of that photo is so good that I can see brown patches in the dips all over the place. Fact is - there is little point in trying to do any painting other than emergency patching at this time of year. I think I've said it several times but perhaps you missed it. The quality of the steel prep only has to be as good as the capacity of a surface tolerant epoxy to deal with that. There will always be a certain level of rust remaining and the brown patches you see is just flash rust which is well within the capacity of the paint to deal with. Have a look at the preparation instructions for Jotamastic 90 and you'll see it recommend a prep standard of ST 2.5 which the floor of that locker meets. https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.hmgpaint.com/PDF/knowledge-base/KNB0026.pdf&ved=2ahUKEwj2_qqygpfoAhXCUhUIHXazCjwQFjABegQIAxAB&usg=AOvVaw3O_topt7Ce7Y2axU137uL8 28 minutes ago, Murflynn said: Vactan will at least dry and provide a sealing primer that will keep the gremlins away until the temperature and humidity have improved so that a proper job can be done. A proper job being to get rid of all the vactan and rust use a decent epoxy? Edited March 13, 2020 by blackrose Link to comment Share on other sites More sharing options...
matty40s Posted March 13, 2020 Report Share Posted March 13, 2020 (edited) 9 hours ago, blackrose said: . Early on in the project while we were working on prepping the bilges of Steatley we were visited by the head of technical of the Cutty Sark project. In my canal boat naiievity I suggested using vactan and he said "Don't use that crap." It doesnt claim to work on burnt timber. Edited March 13, 2020 by matty40s 2 Link to comment Share on other sites More sharing options...
matty40s Posted March 13, 2020 Report Share Posted March 13, 2020 (edited) Dubble post Edited March 13, 2020 by matty40s Link to comment Share on other sites More sharing options...
dmr Posted March 13, 2020 Report Share Posted March 13, 2020 10 hours ago, blackrose said: I A surface tolerant epoxy primer will go over that very nicely. I did not get my locker bottoms nearly as good as that in some places and 3 years on they still look perfect. I did the front well deck about 5 years ago and last year it started to fail in a couple of places with small very localised bubbling. This might have been due to less than perfect prep, or possibly bits of dirt/grit etc bridging the epoxy, or even impact damage. Its relatively easy to do repairs but obviously best done when mixing epoxy for some other project. It was interesting to see that when I ground away the bubbled epoxy there was very little rust on the underlying steel. and... about 8 year ago I did a bit of bilge in red Owatrol (CIP) with Danboline on top. The prep was removing loose rust but not going back to bare metal due to very limited access. That is just starting to fail now. ...............Dave Link to comment Share on other sites More sharing options...
Higgs Posted March 13, 2020 Report Share Posted March 13, 2020 I realise it probably isn't the easiest thing to do, down in a locker, but certainly on a deck, I would epoxy fill the pitting. This is to avoid puddling and trapping water. Link to comment Share on other sites More sharing options...
dmr Posted March 13, 2020 Report Share Posted March 13, 2020 13 minutes ago, Higgs said: I realise it probably isn't the easiest thing to do, down in a locker, but certainly on a deck, I would epoxy fill the pitting. This is to avoid puddling and trapping water. Epoxy is so good at handling standing water that there is no need for this, but it does tend to mostly fill the pits anyway. My lockers get wet everytime we go through a very turbulent lock so they spend a lot of their time a bit wet. ................Dave 1 Link to comment Share on other sites More sharing options...
Higgs Posted March 13, 2020 Report Share Posted March 13, 2020 (edited) 58 minutes ago, dmr said: Epoxy is so good at handling standing water that there is no need for this, but it does tend to mostly fill the pits anyway. My lockers get wet everytime we go through a very turbulent lock so they spend a lot of their time a bit wet. ................Dave My objective would be to avoid the reoccurrence of the problem that caused the rusting, if at all possible. The second objective would be to make something appear as good as new: This may not be a desirable effect, on an older more historic boat. Edited March 13, 2020 by Higgs Link to comment Share on other sites More sharing options...
dmr Posted March 13, 2020 Report Share Posted March 13, 2020 8 minutes ago, Higgs said: My objective would be to avoid the reoccurrence of the problem that cased the rusting, if at all possible. The second objective would be to make something appear as good as new: This may not be a desirable effect, on an older more historic boat. The big plus for epoxy is that its virtually waterproof so recurrence of rusting should not occur. Ordinary paints are not fully waterproof and fail with standing water. Leave a bag of coal on the roof over winter (to trap water under it) and you will mot likely see a bit of paint bubbling by the spring. And I am one of those sad types who tries to make my boat look a bit old rather than like new whenever I do any painting. ? .................Dave 1 Link to comment Share on other sites More sharing options...
Higgs Posted March 13, 2020 Report Share Posted March 13, 2020 2 minutes ago, dmr said: The big plus for epoxy is that its virtually waterproof so recurrence of rusting should not occur. Ordinary paints are not fully waterproof and fail with standing water. Leave a bag of coal on the roof over winter (to trap water under it) and you will mot likely see a bit of paint bubbling by the spring. And I am one of those sad types who tries to make my boat look a bit old rather than like new whenever I do any painting. ? .................Dave Paint needs to be kept ventilated, but epoxy is more robust. There's no harm in fashioning the paintwork to imitate older lines. It isn't always possible to get away with it, but.. Link to comment Share on other sites More sharing options...
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