DIY epoxy blacking.

[matty40s]

Ignore the prices this was the info from 2 years ago...

 

Epidac 116 Black - £49.27 per 5L composite pack (4L base + 1L activator) - this is the product to go over Comastic.

 

Any areas of bare metal with the comastic would ideally be spot primed with our Epidac 115 Aluminium which is £52.34 per 5L composite pack. This gives the anti-corrosion protection to bare steel

[blackrose]

17 hours ago, barmyfluid said:

 

Seriously though, I'm well impressed with Vinyguard, which definitely IS meant to be used over bitumen.

 

Yes, I've been saying for many years that for those sticking with bitumen (no pun intended), the use of a single pack underwater primer makes sense. A couple of coats of either Jotun Vineyguard or International Primocon (same stuff) which can be used around the waterline or over bare steel patches can help extend bitumen lifespan for about an extra year.

 

Your bitumen may get scraped off or eventually degrade with UV light but the primer will stay on for longer protecting the steel. There's no problem going over existing well adhered bitumen either - around the edges of a rust patch you've taken back to bare metal for example. I used to thin the first coat down with 10% thinners. I can't remember what the correct thinners are for these primers but it's definitely not white spirit. I think it's xylene based.

 

 

[rusty69]

I'm getting awful confused here (not difficult, I must admit). Could someone help?

 

Reading about the Ballastic epoxy from SML paints, the data sheet (see attached) suggest it is Epidac 2 HB 90-294 Epoxy. And the SML website says:

 

Quote

This advanced product bridges the gap between having to sand, or blast back, a steel canal boat to bare metal before applying a two-pack epoxy primer, for a 10 year paint system and having to apply a bitumen-based product every year or so. Ballastic Epoxy is a two-pack primer but it can be applied over existing bitumen paint and has all the protection of an epoxy primer which will allow the use of better quality two-pack topcoats.

 

However, having found a previous post by @Dacrylate Paints Ltd , they say:

 

Quote

The Epidac 2 HB Epoxy 90-294 is designed to go over all existing coatings (except bitumen), even those of other manufacturers. It is surface and moisture tolerant and if the boat is re-floated a bit too quickly.... don't worry, it will continue to cure underwater.

 

So, is this simply a case that the product has been changed since that comment was made in 2019 so that it is now suitable to be applied over existing bitumen?

 

Thread here:

 

 

Ballastic Epoxy Safety.pdf

Edited January 30, 2023 by rusty69

[blackrose]

The only epoxy products I know and understand well are Jotun so I'm afraid I can't offer any advice.

 

Except that I can't help thinking that most surface tolerant epoxies could probably be painted over bitumen - on the basis that they won't react. The reason that's not advised by the manufacturers is because adhesion to the steel is of paramount importance for the whole paint system's barrier properties and longevity. So if your base coat is old bitumen you just don't know how well it's adhered to the steel or how long it will remain adhered.

 

How the Ballistic manufacturer can claim a 10 year lifespan of a product that's been painted over an unknown coating with unknown adhesion to the steel seems like a claim too far to me. 

[rusty69]

14 minutes ago, blackrose said:

The only epoxy products I know and understand well are Jotun so I'm afraid I can't offer any advice.

 

Except that I can't help thinking that most surface tolerant epoxies could probably be painted over bitumen - on the basis that they won't react. The reason that's not advised by the manufacturers is because adhesion to the steel is of paramount importance for the whole paint system's barrier properties and longevity. So if your base coat is old bitumen you just don't know how well it's adhered to the steel or how long it will remain adhered.

 

How the Ballistic manufacturer can claim a 10 year lifespan of a product that's been painted over an unknown coating with unknown adhesion to the steel seems like a claim too far to me. 

 

That's the conclusion I came to as well. I was trying to determine if the Dacrylate epidac stuff is the ballastic stuff offered by SML paints.

 

Even though Mr dacrylate has viewed this thread a number of times today, the silence is deafening.

[beerbeerbeerbeerbeer]

When you going in for blacking?

 

 

[rusty69]

1 minute ago, Goliath said:

When you going in for blacking?

 

 

Me? Not until the summer.

[beerbeerbeerbeerbeer]

5 minutes ago, rusty69 said:

Me? Not until the summer.

lots of time to work it out then

 

..but if you’re anything like me you’ll still not have decided 😃

[Tony1]

 

 

Just thought I'd update you on my plans- I'm booking into Northwich Dry Dock for July, and I've decided to go for their epoxy paint option.

Since I can't guarantee getting some extra help this far ahead of the time, I'll pay for them to do the labour as well.

They are covered so rain shouldn't be too much of a problem, and their schedule allows three days for it to dry off before going back in the water. 

Its not a bad price, at £350 for the dry dock and £1165 for the full treatment including baseplate, so just over £1500 (that's only for a 50ft boat though).

They also charge £25 for the electric hookup, which I might not need with all my panels- its a high roof with open sides and there might well be enough sun poking in the sides to charge the batteries. 

Brian and the Haggises have used them, among others, and it does seem a reasonably long lasting treatment, good for at least 4 years and maybe more. 

I'm not kidding myself about the longevity, I can't see how it would last 10 years or more like an epoxy over bare metal.

But even if if it lasts 4 or 5 years, the pricing still compares well to bitumen, when you factor in haul out costs saved, extra level of protection gained, and that the price includes the baseplate, etc.  

Their PDF info leaflet mentions the common concerns about epoxy covering existing bitumen, and they say that they have checked with ands gotten approval from the main epoxy suppliers that their very high pressure wash will leave the surface suitably prepped for epoxy to adhere well, even if all the bitumen is not removed. 

 

Overall, I would describe it as definitely not being a perfect 10 year solution like bare metal treatment, but nevertheless it does look like an effective and very good value compromise, and they do have a very good reputation. 

 

If I could guarantee getting help I would have preferred to haul out for 2 weeks, hire a sandblaster, and get it back to bare metal (I'd love to blast out any rust from the pits etc), but without wheeled transport and extra muscle, I don't really fancy the DIY route.  

They seem a very professional outfit and there are enough very satisfied customers that I can go into there with a lot of confidence that the job will be done well. 

 

ETA- I've just realised the dry dock is not covered, so if we get a few days of rain that will be an issue. But they do say they have always managed to get the boats completed on time, and they work all year round. Fingers crossed its a dry week. 

 

Edited February 1, 2023 by Tony1

[rusty69]

Thanks for the update. 

 

I emailed SML paints, and they suggested their ballastic epoxy, which they say is a bespoke product developed by SML, is likely to offer a 5 year lifespan over prepared bitumen. 

 

They have yet to advise if it is the same product as the Dacrylate Epidac epoxy, or modified in some way. 

Edited February 1, 2023 by rusty69

[matty40s]

I'm pretty sure the Dacrylate is a separate product. Did they send you an information sheet or product spec sheet??

[rusty69]

9 minutes ago, matty40s said:

I'm pretty sure the Dacrylate is a separate product. Did they send you an information sheet or product spec sheet??

 

No, they didn't. All I have is the link that I already posted from their website, which refers to 'epidac 2HB 90-294'. I have attached it again.

 

I can only assume, until advised otherwise by @Dacrylate Paints Ltd or SML that it is not the same product, though the numbers are very similar.

 

So far, neither Dacrylate or SML  have replied.

Ballastic Epoxy Safety (5) (1).pdf

Edited February 1, 2023 by rusty69

[rusty69]

2 hours ago, Tony1 said:

If I could guarantee getting help I would have preferred to haul out for 2 weeks, hire a sandblaster, and get it back to bare metal (I'd love to blast out any rust from the pits etc), but without wheeled transport and extra muscle, I don't really fancy the DIY route.  

Well, whilst you are having the week off, if you fancy coming to help us with ours..............

[David Mack]

2 hours ago, Tony1 said:

ETA- I've just realised the dry dock is not covered, so if we get a few days of rain that will be an issue.

Well the middle bit is, but the railway viaduct is so high that I doubt you'll get much of a dry spot under it.

In the video earlier in the thread they did get rained off a couple of days.

[Tony1]

1 minute ago, rusty69 said:

Well, whilst you are having the week off, if you fancy coming to help us with ours..............

 

 

To be honest, they normally do the pressure wash on saturday morning, so I'm going to ask them if its worth me going around the hull just after the wash with a wire brush disc on my grinder, to see if I can scrub off any significant patches of rust. My thinking is I can always wash it down afterwards. 

But that said, I dont want to interfere with a well-proven process, and my concern might be that the wire brush might smear any existing bitumen around, make a mess, and maybe leave the surface in a worse condition for the epoxy. Worth asking them though.

 

 

 

 

[rusty69]

1 minute ago, Tony1 said:

 

 

To be honest, they normally do the pressure wash on saturday morning, so I'm going to ask them if its worth me going around the hull just after the wash with a wire brush disc on my grinder, to see if I can scrub off any significant patches of rust. My thinking is I can always wash it down afterwards. 

But that said, I dont want to interfere with a well-proven process, and my concern might be that the wire brush might smear any existing bitumen around, make a mess, and maybe leave the surface in a worse condition for the epoxy. Worth asking them though.

 

 

 

 

Well, mr dacrylate is reading this thread right now. You might get it straight from the horses mouth if you are lucky.

[Tony1]

7 minutes ago, David Mack said:

Well the middle bit is, but the railway viaduct is so high that I doubt you'll get much of a dry spot under it.

In the video earlier in the thread they did get rained off a couple of days.

 

Yes, thanks David, I since realised my mistake about that. 

I can only hope we get a mostly dry week, really. I did ask about booking two weeks as a contingency to give more waiting/drying time if needed, but he was confident they could do a more than satisfactory job within the week- and they no longer have slots available anyway, so its fingers crossed. 

 

 

[Jon57]

11 minutes ago, Tony1 said:

 

Yes, thanks David, I since realised my mistake about that. 

I can only hope we get a mostly dry week, really. I did ask about booking two weeks as a contingency to give more waiting/drying time if needed, but he was confident they could do a more than satisfactory job within the week- and they no longer have slots available anyway, so its fingers crossed. 

 

 

And more money for them doing another blacking job.👍

[beerbeerbeerbeerbeer]

Here you go rusty69, this is what happens mixing epoxy and bitumen!

Can happen in two weeks or two years. 
But it’s sudden death 💀  either way 
 

[Rob-M]

2 hours ago, Goliath said:

Here you go rusty69, this is what happens mixing epoxy and bitumen!

Can happen in two weeks or two years. 
But it’s sudden death 💀  either way 
 

Is that the one on the Stourbridge...?

[matty40s]

21 hours ago, rusty69 said:

Well, mr dacrylate is reading this thread right now. You might get it straight from the horses mouth if you are lucky.

This is what I have used since Comastic was removed from the planet.

 

 

 

It is a high huild epoxy coat that can cover chlorinated rubber, vinyl, acrylated rubber, oleo resinsous, alkyds, silicone alkyds, and similar. It is a Highways England product.

It is not the same as the SML product to my knowledge.

[rusty69]

24 minutes ago, matty40s said:

This is what I have used since Comastic was removed from the planet.

 

 

 

It is a high huild epoxy coat that can cover chlorinated rubber, vinyl, acrylated rubber, oleo resinsous, alkyds, silicone alkyds, and similar. It is a Highways England product.

It is not the same as the SML product to my knowledge.

 

Thanks for that. I think I am going to use one of the Jotun products, probably Jotmastic 90.

Whilst I have been able to determine that the SML ballistic epoxy is not the same as the Dacrylate epidac 2 HB 90-294 (though the numbers are the same),  it has similarities, according to SML.

 

The comment made by dacrylate paints that 2 HB 90-294 is NOT designed to go over bitumen, and their reluctance to comment has left me a bit suspicious.

[LadyG]

On 29/01/2023 at 16:27, rusty69 said:

I'm grateful for all input. As I say, I've never done this before, so its all a bit daunting.

 

If I can, I will go the jotun route with the hydroblaster thing if I can get it clean enough.

 

If I can't, I will likely opt for the ballastic stuff, concentrating on the area around and below the waterline.

 

 

 

But this assumes you have time to wait for delivery, unless somewhere local stocks everything. When I started I had my kit (SML paints) ready to start, and Day 1 was out, wash, and wire brushed by yard. Day 2, 3 4 ... three coats to use up all the epoxy. Then curing and launching. Eight days, paying by the day, I was lucky as it was a bank holiday so I got an extra day, the yard normally work on a weekly turnaround.

I should have been ready with masking tapes and paints for gunwales, as I had three days just doing very little. 

 

[rusty69]

3 hours ago, LadyG said:

But this assumes you have time to wait for delivery, unless somewhere local stocks everything. When I started I had my kit (SML paints) ready to start, and Day 1 was out, wash, and wire brushed by yard. Day 2, 3 4 ... three coats to use up all the epoxy. Then curing and launching. Eight days, paying by the day, I was lucky as it was a bank holiday so I got an extra day, the yard normally work on a weekly turnaround.

I should have been ready with masking tapes and paints for gunwales, as I had three days just doing very little. 

 

That is true, and a good point. We are out for 2 weeks, and having used SML paints in the past, and know their delivery is pretty good, though there is obviously some risk relying on a courier. 

 

Anyway. Have decided to go the jotun route, so will buy all we need prior to the boat coming out. 

[rusty69]

On 27/01/2023 at 17:01, Jon57 said:

I’ve used the Tercoo triple on my hull. It’s a good bit of kit for getting down to bare steel, but slow progress and dusty. Doesn’t like false rivets or tight edges as it can damage the tungsten teeth so save them till last, or use a single Tercoo.  Two would possibly do a 70ft Narrowboat sides only. I used the SML ballistic black epoxy that goes over existing blacking. I’m doing the baseplate on mine in May so will Know how it’s performed. Did mine (56ft) in a week with help but it was hard work.

 

Would be interested to know..........

 

On 27/01/2023 at 17:26, ditchcrawler said:

I am in the dry dock for reblacking this  May, I had it done with 2Pk over bitumen 4 years ago following high pressure power wash. The decision on whether to go 2pk again or straight bitumen I will make after its been washed off. From what I can see with it afloat it will be 2pk again but I wont know until May.

 

what the results were?