Steel degreasing prior to painting

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Jegs

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Got some rust to remove in the spring & intend to apply International's Interprotect onto the bare metal & it seems they recommend their general purpose "Yacht Line Super Cleaner" to degrease before painting. I was planning to use acetone but this product may be better; anyone care to opine?

Hopeful thanks,

John G
 
earlybird said:
Supercleaner is not intended for bare metal AFAIK.
Grit blasting is best for cleaning steel prior to two pack epoxy.
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Thank you for your response; unfortunately grit blasting is not practical due to area of work, two separate strips 12mm x 6000mm, & the location of the boat.

John G
 
Jegs said:
Got some rust to remove in the spring & intend to apply International's Interprotect onto the bare metal & it seems they recommend their general purpose "Yacht Line Super Cleaner" to degrease before painting. I was planning to use acetone but this product may be better; anyone care to opine?

Hopeful thanks,

John G
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Super Cleaner is a concetrate to be diluted with water and used to remove wax or oily contamination prior to grit blasting http://www.yachtpaint.com/MPYACMDatasheets/Super_Cleaner+eng+A4+Y+20141215.pdf


Steel surfaces should be degreasd with Super Cleaner and grit blasted or ground with abrasive discs before applying Interprotect http://www.yachtpaint.com/MPYACMDatasheets/Interprotect+eng+A4+Y+20150902.pdf
 
VicS said:
Super Cleaner is a concetrate to be diluted with water and used to remove wax or oily contamination prior to grit blasting http://www.yachtpaint.com/MPYACMDatasheets/Super_Cleaner+eng+A4+Y+20141215.pdf


Steel surfaces should be degreasd with Super Cleaner and grit blasted or ground with abrasive discs before applying Interprotect http://www.yachtpaint.com/MPYACMDatasheets/Interprotect+eng+A4+Y+20150902.pdf
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Cont'd later:

For other substrates solvent or Super Cleaner is recommended , but of course they wont rust if a water based cleaner is used .

Since they don't specify what solvent anything you have to hand from white spirit to acetone should be Ok. Personally not over keen on acetone because it is so volatile. I'd clean a heavily contaminated surface with a less volatile solvent such as white spirit followed perhaps with a final wipe with acetone to remove any residue.

However you do need to apply the Interprotect to a clean rust free surface.
 
>Thank you for your response; unfortunately grit blasting is not practical due to area of work, two separate strips 12mm x 6000mm, & the location of the boat

If you can't get back to bare metal and use a zinc rich epoxy undercoat then it is only a matter of time before the rust comes back. If you want to get back to bare metal use a grinder when the humidity is low and get the paint on fast, otherwise you risk flash rusting.
 
Gentlemen,

My thanks to all of you for helpful replies. The work will be done in a heated workshop & I'll start with a wire brush then a disc in the < grinder - the fact that it's a long thin strip, effectively a bilge keel edge, makes it somewhat difficult for one with 9.5 thumbs. Acetone for final degrease then Interprotect, then thumbs crossed.

ATB,

John G
 
Jegs said:
Gentlemen,

My thanks to all of you for helpful replies. The work will be done in a heated workshop & I'll start with a wire brush then a disc in the < grinder - the fact that it's a long thin strip, effectively a bilge keel edge, makes it somewhat difficult for one with 9.5 thumbs. Acetone for final degrease then Interprotect, then thumbs crossed.

ATB,

John G
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Worth considering treating it with phosphoric acid after grinding as well. Even with a grinder there will probably still be some rust there. On a hot day with what looks like shiney clean steel you'll see the acid bubbling away in the pits. Wickes tile grout film remover is a handy local source. On a steel boat I'll do that a couple of times, then a really good wash, let dry and wipe down with acetone then run a blowtorch over it just before painting.
 
GHA said:
Worth considering treating it with phosphoric acid after grinding as well. Even with a grinder there will probably still be some rust there. On a hot day with what looks like shiney clean steel you'll see the acid bubbling away in the pits. Wickes tile grout film remover is a handy local source. On a steel boat I'll do that a couple of times, then a really good wash, let dry and wipe down with acetone then run a blowtorch over it just before painting.
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Thank you, but the workshop is only available for two consecutive days & I fear that such a thorough method, together with painting, would not be possible in the time available.

ATB,

John G
 
>I'll start with a wire brush...Interprotect

No a steel brush leaves tiny bits of metal only use the grinder after that it doen't need degreasing. Also don't use Interprotect only zinc rich epoxy will protect steel and if you use that rust will come and you will have to start all over again. This comes from the experience of owning a steel ketch.
 
KellysEye said:
>I'll start with a wire brush...Interprotect

No a steel brush leaves tiny bits of metal only use the grinder after that it doen't need degreasing. Also don't use Interprotect only zinc rich epoxy will protect steel and if you use that rust will come and you will have to start all over again. This comes from the experience of owning a steel ketch.
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B......r, £30 to int paints for something they claim will do the job. More importantly, thank you very much for sharing your experience in the matter. I shall start looking for a zinc rich epoxy tomorrow.

ATB,

John G
 
If you are going to use wire brushes, ensure they are Stainless steel wire brushes because the debris from the normal brushes will start rust all over the place and on any neighbour’s boat

And use Phosphoric acid after brushing/grinding, if the steel is still shiny after 8 hours then apply a good 2 pack primer like International.

If there are black bits left on the steel then rust is still present , brush/grind until it stays shiny then prime

Owner of a steel boat for 23 years

Good luck
 
Frosts sell a good degreaser called POR 15 MarineClean. Use with hot water if possible. I think it works better than acetone unless you have a big supply of acetone - otherwise the acetone just dilutes but redistributes the grease / oil.
 
john_q said:
If you are going to use wire brushes, ensure they are Stainless steel wire brushes because the debris from the normal brushes will start rust all over the place and on any neighbour’s boat

And use Phosphoric acid after brushing/grinding, if the steel is still shiny after 8 hours then apply a good 2 pack primer like International.

If there are black bits left on the steel then rust is still present , brush/grind until it stays shiny then prime

Owner of a steel boat for 23 years

Good luck
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Thank you for your advice. The work is being done in a hired workshop available for two days only; other boats will be safe but 8 hour delay before priming will not be feasible.

Many thanks,

John G
 
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Avocet said:
Frosts sell a good degreaser called POR 15 MarineClean. Use with hot water if possible. I think it works better than acetone unless you have a big supply of acetone - otherwise the acetone just dilutes but redistributes the grease / oil.
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Thank you, I shall order some tomorrow.

ATB,

John G
 
>Frosts sell a good degreaser called POR 15 MarineClean.

As I said above after grinding no degreaser is required and thus a waste of money.

>then apply a good 2 pack primer like International.

No as I said above use zinc rich epoxy otherwise the rust will come back. Jegs has already said that is what he will buy.

Also there is no need for any brush stainless or not if grinding or phosphoric acid. It serves no purpose and would be have to be washed off before painting on the Zinc epoxy. The last thing you want to is put on bare steel is water..
 
KellysEye said:
Also there is no need for any brush stainless or not if grinding or phosphoric acid. It serves no purpose and would be have to be washed off before painting on the Zinc epoxy. ..
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That's simply not the case. Try it. Grind til you think it's shiney clean bare metal and put some acid on it. If it's warm enough you will see the acid fizzing in the pits with rust which is left, unseen. Also, zinc epoxy is nowhere near the be all and end all, there are much better primers available with far superior adhesion qualities, also with zinc rich if you get a dink in the paint then the zinc will corrode creating a larger area of damage than without.
 
>there are much better primers available with far superior adhesion qualities, also with zinc rich if you get a dink in the paint then the zinc will corrode creating a larger area of damage than without.

As I've said a number of times any primer other than Zinc rich exopy will allow rust to come back, if you or anyone wants to do that please carry on. It is normal to use two coats of Zre and we then put three coats of antifouling on top. If you were to get a dink the zinc it wouldn't corrode because of the epoxy which is why you can use it in the first place.
 
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