Which 2-pack?

[bobtom]

Next month I am due to have my boat in for the 2-pack to be re-coated. However, the boatyard are insistent that they cannot guarantee the job without knowing which 2-pack is on there.

As I don't have this information can anyone suggest which one I use. Or does it really matter?

[Tracy D'arth]

1 hour ago, bobtom said:

Next month I am due to have my boat in for the 2-pack to be re-coated. However, the boatyard are insistent that they cannot guarantee the job without knowing which 2-pack is on there.

As I don't have this information can anyone suggest which one I use. Or does it really matter?

How the devil would we know then?  Where was it done last? Who did it? Have you asked them? Is there any tin with remains in? Have you written it down anywhere? Do you have an invoice with it on? Have you tried a ouija board?

Do you know how many brands and formulations of 2 pack epoxy there are?

[system 4-50]

1 hour ago, bobtom said:

Next month I am due to have my boat in for the 2-pack to be re-coated. However, the boatyard are insistent that they cannot guarantee the job without knowing which 2-pack is on there.

As I don't have this information can anyone suggest which one I use. Or does it really matter?

As long as you are sure that it was a 2-pack, I would not worry about it and would use a Jotun flavour.  Your boatyard knows perfectly well that you can't give this info and is just using it as an excuse for refusing to give a guarantee.  Check that they don't put it back in the water before the time on the tin.

[bobtom]

28 minutes ago, Tracy D'arth said:

How the devil would we know then?  Where was it done last? Who did it? Have you asked them? Is there any tin with remains in? Have you written it down anywhere? Do you have an invoice with it on? Have you tried a ouija board?

Do you know how many brands and formulations of 2 pack epoxy there are?

I don't know anything about 2-pack so thought I would ask on here for any advice that someone might be able to offer.

As to your next 3 questions the answer is I don't know.

To the rest of your questions the answer is no.

31 minutes ago, system 4-50 said:

As long as you are sure that it was a 2-pack, I would not worry about it and would use a Jotun flavour.  Your boatyard knows perfectly well that you can't give this info and is just using it as an excuse for refusing to give a guarantee.  Check that they don't put it back in the water before the time on the tin.

Thanks for that. I will probably go with that then.

 

As I understand it the boatyard in question has a good reputation so I don't think that they are trying to fob me off. So I will just have to accept that there may not be a guarantee

 

I did phone around a number of boatyards but, unfortunately, they don't keep these sorts of records. Tony Barber, on the Alrewas, told me that so long as they run it down then it should be ok.

[LadyG]

I think the main thing is to ensure that the current coat is epoxy and absolutely not bitumen. I believe the test is a rag soaked in a solvent .

Not sure what guarantee can stand the rough and tumble of the cut .

I would have thought any two pack epoxy would be stable by now but bitumen would not be suitable 

Best ask the paint experts free technical advice from experts is better than a guess.  

Some two pack epoxies may be more surface tolerant than others .

Edited August 18, 2023 by LadyG

[PeterF]

We have been offered Hempadur 45143 and Hempel said it was good for use on other 2-pack epoxy blackings as long as the previous coat was adherent and was mechanically abraded before coating. The work is planned for next year so I do not have proof of this.

[bobtom]

18 minutes ago, PeterF said:

We have been offered Hempadur 45143 and Hempel said it was good for use on other 2-pack epoxy blackings as long as the previous coat was adherent and was mechanically abraded before coating. The work is planned for next year so I do not have proof of this.

Thanks for that. I'll mention that to him and see what he says.

[blackrose]

Jotamastic 90 will go on top of must other epoxies but you must give any existing epoxy coating a good key first with a sander and a medium grit paper say 180grit. Dust the surface well after sanding.

 

Make sure you (and whoever is doing the work) read and understand the technical data sheet before starting. Pay particular attention to mixing and minimum /maximum overcoating times.

 

https://www.jotun.com/gb-en/industries/products/Jotamastic-90

 

I recommend you use a winter grade hardener (Jotun have a choice of standard or winter grade) because standard grade requires a full week out the water to fully cure before the boat goes back in the water even at about 20 degrees. Get yourself some Jotun thinners 17 as well.

 

If you need more information send me a PM

 

 

 

 

[TheBiscuits]

19 hours ago, PeterF said:

We have been offered Hempadur 45143 and Hempel said it was good for use on other 2-pack epoxy blackings as long as the previous coat was adherent and was mechanically abraded before coating. The work is planned for next year so I do not have proof of this.

 

I've done this over a previous, no longer available 2-pack.  It does need to be thoroughly cleaned before and after grinding/ abrading and I've only lost bits of it where bits of canal infrastructure got in the way

 

I've used it, and this technique of several other boats too and have always been pleased with the results.

 

Usually get it from King's Lock chandlery, and will use it again next time.

[dmr]

We were originally done in an International 2 pack (Intertuf?). This was repaired and then another two coats of Jotun 87 put on top.

At the next repair docking it got another coat of Jotun 87 and a coat of Jotun 90. It all appears to mix and match and stay on pretty well.

I assume at some stage it will all have to come off and start again but I suspect shot blasting all those layers of epoxy will be hard work.

[blackrose]

4 hours ago, dmr said:

I assume at some stage it will all have to come off and start again but I suspect shot blasting all those layers of epoxy will be hard work.

 

If it's still bonded to the hull well then it can just be keyed. If it's coming off then make sure any yard you take it to has a powerful compressor otherwise they'll struggle to get it off.

[dmr]

1 hour ago, blackrose said:

 

If it's still bonded to the hull well then it can just be keyed. If it's coming off then make sure any yard you take it to has a powerful compressor otherwise they'll struggle to get it off.

I don't know what the ultimate failure mode is. If its not quite 100% waterproof then water will get in and cause a bit of rusting causing it to lift off, and maybe the sunshine degrades the exposed bits, but if we recoat every few years then maybe this will offset any problems and it will last for almost ever.

[LadyG]

On 18/08/2023 at 16:00, blackrose said:

Jotamastic 90 will go on top of must other epoxies but you must give any existing epoxy coating a good key first with a sander and a medium grit paper say 180grit. Dust the surface well after sanding.

 

Make sure you (and whoever is doing the work) read and understand the technical data sheet before starting. Pay particular attention to mixing and minimum /maximum overcoating times.

 

https://www.jotun.com/gb-en/industries/products/Jotamastic-90

 

I recommend you use a winter grade hardener (Jotun have a choice of standard or winter grade) because standard grade requires a full week out the water to fully cure before the boat goes back in the water even at about 20 degrees. Get yourself some Jotun thinners 17 as well.

 

If you need more information send me a PM

 

 

 

 

I coated mine with Jotamastic 90 in summer, 23C I'd say, I was on my own and just mixed the tins a few times, stirred with a paint stirrer, and got it on no hassle, I had all the kit ready go including a square paint kettle and long and short 4" roller handles and the right rollers. I would make sure the tins are warm, say 23/25C and buy wintergrade, as mentioned previously and recommended by supplier (SML). 

The ambient temperature  needs to be above Dew Point.

Read Data Sheet.

Edited August 19, 2023 by LadyG