DIY epoxy blacking.

[rusty69]

1 hour ago, n-baj said:

 

if I was in the area Tony I’d give you a hand but I’m currently in Yorkshire.

Quick, get your boat up to Yorkshire Tony.

[n-baj]

1 hour ago, Tony1 said:

 

I'll have you helicoptered in! 

 

 

That’s fine there’s wide open spaces and an airfield nearby😃

 

for comparison I’ve applied epoxy (jotamastic 90) to an untreated 17 year old baseplate (pictured). As you can see it’s not to sandblasted standard but it does state in the data sheet words to the effect of ‘suitable where optimum preparation is not desirable or achievable’. I can’t say it’s worked as I won’t find out until 2025 but that’s how I’ve done it. 

[Clanky]

16 hours ago, rusty69 said:

I dunno. Suspect at full pressure it's in the region of 2000 Bar.

 Do you mean PSI? 2000 bar is nearly 30000psi, which I would suspect would cut through steel🙄 and I doubt very much you would be able to hold it.

Edited June 18, 2023 by Clanky

[ditchcrawler]

2 hours ago, matty40s said:

We have just taken a complete rust bucket  boat back to metal,  and went through 6 packs of those discs, (a out £300!!)

You may find that the pressure washer is at the mercy of the tap water pressure, we have made a large additional reservoir which we run it from, can usually clean half a 60 footer before it runs out, then by the time you have had a cup of tea, has refilled for the other half.

If your washer is filled via a siphon pump from canal, you may find it is just the filter compromising pressure.

Northwich Dry Dock run theirs from a series of IBCs 

[rusty69]

3 hours ago, Clanky said:

 Do you mean PSI? 2000 bar is nearly 30000psi, which I would suspect would cut through steel🙄 and I doubt very much you would be able to hold it.

Nope. Pretty sure I mean 2000 bar at full pressure. I assume the pressure can be altered lower than that value.

[blackrose]

https://techcoatings.co.uk/services/ultra-high-pressure-water-blasting/

[rusty69]

6 hours ago, matty40s said:

You may find that the pressure washer is at the mercy of the tap water pressure, we have made a large additional reservoir which we run it from, can usually clean half a 60 footer before it runs out, then by the time you have had a cup of tea, has refilled for the other half.

If your washer is filled via a siphon pump from canal, you may find it is just the filter compromising pressure.

Just had a closer look at the washer. It has an integral tank with a float valve. The tank capacity isn't huge, maybe100 litres.

[ditchcrawler]

Just now, rusty69 said:

Just had a closer look at the washer. It has an integral tank with a float valve. The tank capacity isn't huge, maybe100 litres.

Did you rent this bit of kit?

[rusty69]

1 minute ago, ditchcrawler said:

Did you rent this bit of kit?

No, its on site. We paid the owner to operate it.

[ditchcrawler]

15 minutes ago, rusty69 said:

No, its on site. We paid the owner to operate it.

I was going to say its a lethal bit of kit to rent out without training, The one they use at Northwich is not that high, only 4500 psi. but they don't try to remove well adhered bitumen 

[rusty69]

1 minute ago, ditchcrawler said:

I was going to say its a lethal bit of kit to rent out without training, The one they use at Northwich is not that high, only 4500 psi. but they don't try to remove well adhered bitumen 

I assume that is why he doesn't allow anyone else to use it.

[blackrose]

7 minutes ago, ditchcrawler said:

The one they use at Northwich is not that high, only 4500 psi. but they don't try to remove well adhered bitumen 

 

That sounds like a pressure washer. An ultra-high pressure water blaster is something different entirely.

[Alan de Enfield]

33 minutes ago, ditchcrawler said:

I was going to say its a lethal bit of kit to rent out without training, The one they use at Northwich is not that high, only 4500 psi. but they don't try to remove well adhered bitumen 

 

A standard scuba air cylinder operates at up to 300 bar (4350 psi) and at that pressure the air is so dense it is vitually a semi-solid.

[Tim Lewis]

On 17/06/2023 at 21:25, Tony1 said:

 

Thanks a lot, its very kind of you to give an update, and I'm really sorry to hear about the snags- and I must say I've run into some snags myself.

I'm booked into have a high pressure wash on 15th July, followed by the 2 pack treatment. 

But I was in an area with much clearer water recently, and I could see significant patches of visible rust below the waterline. 

The boat is about 7 years old so I'm hoping the rust isn't too deep, but with just 4 weeks to go, I'm now in a bit of a jam.

I'm reluctant to cancel my slot, as I don't know if I'll find another (at a decent place) before the cooler weather arrives.

On the other hand, I dont want them to just slap 2 pack on over a rusting surface. 

All I can think of the moment is to wait until the pressure wash is done, and then to spend the rest of that day going over the whole hull (below the waterline) with a grinder (and a flap disc), in the hope of removing as much surface rust as possible before they start the primer etc. 

I wish now that I'd booked a 2 week haul out and had thus allowed plenty of time to remove any rust from the hull, but now I'm going to be really up against it, with at most 8-10 hours after the pressure wash to do whatever I can in terms of preparing the surface. 

I feel like this should really have been a grit blast treatment to do it properly, but their tight 1-week schedule will not allow for any third parties to turn up and spend 2 days blasting. So I'm going to have to revisit the whole thing in another 2 years, instead of maybe 5 years as I was hoping. 

 

 

 

 

 

Have just spent the weekend helping a friend with her blacking. My job on the first day was to remove the surface rust etc using a 4" angle grinder with a twisted wire cup brush. The boat is 45! (I think) and it took me about three hours per side, we then applied Jenolite rust remover where necessary. A second person with another grinder will obviously be a lot quicker.

 

Edited June 19, 2023 by Tim Lewis

[rusty69]

3 hours ago, Tim Lewis said:

. A second person with another grinder will obviously be a lot quicker.

Yes, I found that. Mrs Rusty is much quicker than I am. 

[rusty69]

 

To Finish this subject off and impart my new found wisdom onto any other poor fool who decides to save a few quid and go down the DIY epoxy route and who may aimlessly happen upon this thread.

DON'T DO IT.

Take Alan's advice, the very first reply. Pay a man that can.

If you really want to paint 2 pack epoxy on the hull yourself, then by far the best option would be to pay someone to grit blast it first.

Lessons learnt:

1. Bitumen is a bitch to fully remove with the tools we had at our disposal; particularly if your hull has some pitting. The tools we used included a high power hydro blaster, scrapers, wire cup brushes, flap discs, poly discs, and flat wire brushes. We probably consumed 20 scraper blades,12 wire cup brushes,12 flap discs, 4 flat wire brushes, one poly disc and 22 litres of epoxy, 8 paint brushes and 18 rollers. Various paint buckets/trays, some thinners and quite a few electrons.

2. If doing it again, which I won't, then my tool of choice would be a tercoo rotary blaster.

3. A more sensible approach would have been to 2 pack the part from just above the waterline to the base plate  where the bitumen had less layers and was easier to remove, and leave the part above.Or to just reapply bitumen.Same with the uxter plate, where years of bitumen had built up.

4. We booked two weeks out in an uncovered yard, which was about right. With the various problems, and dodging the odd rain shower, less than 2 weeks would not have been achievable.

5. A covered area would have been much better. A covered heated area, the thing of dreams.Do not paint outside unless you can predict the weather. The forecast is usually not to be trusted. On our first coat there was a 5% chance of rain forecast, which turned into a huge thunderstorm that lasted an hour as soon as we had finished painting.

6. Temperature wise, we had a good week for epoxy curing, with daytime temperatures exceeding 22 degrees and nightimes in the low teens. The choice of winter grade hardener was a good one. Although the pot life is short, which results in a number of batches per coat being required, the subsequent time to reach fully cured is shortened.

 If we had selected standard grade hardener, I would have preferred an extra week.

7. If at all possible, try to vary the colour of the two pack on each coat. It makes it much, much easier to see the bits you have missed. We bought some red tint to add to the Aluminium epoxy, though tinted epoxy is also available.

8. If you can get some extra hands in to help with the prep, things will go much quicker. Ours is a 70ft boat, and with the exception of the hydro blaster and some pit welding, the prep was undertaken solely by me and Mrs R.

9. Our hull is 40 years old, and many people commented that it was in great condition for its age, so we had obviously been doing something right with the tried and tested methods all these years.

10. It is very tempting to buy all the epoxy up front and have it delivered. There is a risk in doing so that you don't make it to your destination due to a lock failure or mechanical breakdown. One of the tins we had delivered was split, and the contents leaked.

Whether 2 pack was worth the cost and effort, only time will tell.

Thankyou to everyone who has contributed to this thread, and a huge thankyou to mr @blackrose who has offered us an immense amount of support behind the scenes.

Good luck to all you DIY epoxiers out there.

Edited June 24, 2023 by rusty69

[Tim Lewis]

39 minutes ago, rusty69 said:

 

To Finish this subject off and impart my new found wisdom onto any other poor fool who decides to save a few quid and go down the DIY epoxy route and who may aimlessly happen upon this thread.

DON'T DO IT.

Take Alan's advice, the very first reply. Pay a man that can.

If you really want to paint 2 pack epoxy on the hull yourself, then by far the best option would be to pay someone to grit blast it first.

Lessons learnt:

1. Bitumen is a bitch to fully remove with the tools we had at our disposal; particularly if your hull has some pitting. The tools we used included a high power hydro blaster, scrapers, wire cup brushes, flap discs, poly discs, and flat wire brushes. We probably consumed 20 scraper blades,12 wire cup brushes,12 flap discs, 4 flat wire brushes, one poly disc and 22 litres of epoxy, 8 paint brushes and 18 rollers. Various paint buckets/trays, some thinners and quite a few electrons.

2. If doing it again, which I won't, then my tool of choice would be a tercoo rotary blaster.

3. A more sensible approach would have been to 2 pack the part from just above the waterline to the base plate  where the bitumen had less layers and was easier to remove, and leave the part above.Or to just reapply bitumen.Same with the uxter plate, where years of bitumen had built up.

4. We booked two weeks out in an uncovered yard, which was about right. With the various problems, and dodging the odd rain shower, less than 2 weeks would not have been achievable.

5. A covered area would have been much better. A covered heated area, the thing of dreams.Do not paint outside unless you can predict the weather. The forecast is usually not to be trusted. On our first coat there was a 5% chance of rain forecast, which turned into a huge thunderstorm that lasted an hour as soon as we had finished painting.

6. Temperature wise, we had a good week for epoxy curing, with daytime temperatures exceeding 22 degrees and nightimes in the low teens. The choice of winter grade hardener was a good one. Although the pot life is short, which results in a number of batches per coat being required, the subsequent time to reach fully cured is shortened.

 If we had selected standard grade hardener, I would have preferred an extra week.

7. If at all possible, try to vary the colour of the two pack on each coat. It makes it much, much easier to see the bits you have missed. We bought some red tint to add to the Aluminium epoxy, though tinted epoxy is also available.

8. If you can get some extra hands in to help with the prep, things will go much quicker. Ours is a 70ft boat, and with the exception of the hydro blaster and some pit welding, the prep was undertaken solely by me and Mrs R.

9. Our hull is 40 years old, and many people commented that it was in great condition for its age, so we had obviously been doing something right with the tried and tested methods all these years.

10. It is very tempting to buy all the epoxy up front and have it delivered. There is a risk in doing so that you don't make it to your destination due to a lock failure or mechanical breakdown. One of the tins we had delivered was split, and the contents leaked.

Whether 2 pack was worth the cost and effort, only time will tell.

Thankyou to everyone who has contributed to this thread, and a huge thankyou to mr @blackrose who has offered us an immense amount of support behind the scenes.

Good luck to all you DIY epoxiers out there.

 

Aylesbury Canal Society has a covers heated (And ventilated) dock at Circus Fields Marina!

 

Slipway (Dry dock) – Aylesbury Canal Society

 

[Bargebuilder]

On 27/01/2023 at 16:33, rusty69 said:

I have looked into various coatings , and have discounted the chemco glass flake epoxy, and the Sherwin Williams epoxy on cost grounds.

Just in case readers are looking to undertake a similar operation, I wouldn't exclude the Chemco surface tolerant primer on the basis of cost. Given the massive effort required and/or cost involved with preparing the steel, a primer that covers and seals as well as the Chemco product, although pricey, may be seen as excellent value, especially in hindsight!

 

When my boat was ashore in the boat yard, there was an old steel motor launch next to it and he prepared the hull to a fairly high standard, but by the time he got round to priming it with Chemco primer, it was brown with rust all over once more. The chap arrived with the two pack product, a tray and rollers and set to work. After an hour or two it started raining and he continued to paint the wet, rusty steel hull. The rain worsened and the paint in his tray began to cover with rain water. He carried on, pushing the roller through the water to pick up the primer. I watched with interest as he finished painting the wet hull and drove off. The boat looked great in its new silver/grey livery, but I thought to myself, it'll never last.

 

That boat remained untouched in the yard for about three years and I kept an eye on the paint job all that time. It only had a single coat of primer and in those three years it never had a top coat, but when I saw it last there was no sign of rust anywhere. 

 

If anything can be learnt from this, it is that if you are not sure about how well you are going to be able to do the preparation work, or simply don't intend to spend the time necessary to achieve a perfect finish, buy the best surface tolerant primer.

 

I applied the Chemco glass flake primer/topcoat combination to my barge in 2011 and there is zero corrosion anywhere so far. The manufacturer suggests it could be good for 25 years and given its performance so far, I wouldn't be at all surprised.

[rusty69]

1 hour ago, Bargebuilder said:

On 27/01/2023 at 16:33, rusty69 said:

 

Just in case readers are looking to undertake a similar operation, I wouldn't exclude the Chemco surface tolerant primer on the basis of cost.

Of course you wouldn't, and obviously didn't. That is not to say everyone has the same budget as you. The paint alone is only one part of the cost. For me, I had to include the cost of 2 weeks on a trailer, a rather expensive high pressure washer, all the consumables. Compared to bitumen it was a much bigger outlay.

 

Hopefully in the long run it will pay for itself. But who is to say the epoxy I used will also not last a considerable amount of time.

 

As I said in my last post, only time will tell. 

[Bargebuilder]

1 hour ago, rusty69 said:

Compared to bitumen it was a much bigger outlay.

Absolutely right, compared to blacking it is expensive, but I thought you said that you had excluded Chemco glassflake, but applied a different two pack epoxy coating. 

 

Is the Chemco surface tolerant primer very much more than other 2 pack epoxy hull coatings?

 

I was trying to highlight that the Chemco product can be applied to relatively poorly prepared surfaces and in atrocious weather conditions, two attributes that might have made your life a bit easier.

[rusty69]

2 hours ago, Bargebuilder said:

Absolutely right, compared to blacking it is expensive, but I thought you said that you had excluded Chemco glassflake, but applied a different two pack epoxy coating. 

 

Is the Chemco surface tolerant primer very much more than other 2 pack epoxy hull coatings?

 

I was trying to highlight that the Chemco product can be applied to relatively poorly prepared surfaces and in atrocious weather conditions, two attributes that might have made your life a bit easier.

 

When I contacted chemco, their commercial coordinator advised me of the following. He mentioned nothing about mixing with water, or applying in the rain:

 

All existing coating must be removed and bare steel exposed
Surface to be cleaned and free from all contaminations including oil and grease
Surface to be prepared to minimum St2 – but more optimal surface preparation increases life expectancy of system (such as WJ2 / St3)
Apply one coat of RS 500P at 100 microns
Apply two coats of RA 500M at 250 microns each (500 microns total)
Corners, edges, and weld areas to be stripe coated with same coatings
Surface must be fully cured before being put into service

 

They do not appear to be vastly different from the jotamastic 90 that I ended up using.

 

At the time I requested a quote from chemco, their costs were:

 

For 50m² surface area you’ll require minimum:

 

RS 500P – 10kg

RA 500M – 40kg (20kg per coat)

 

Pricing (ex-works) is as follows:

               RS 500P – £15.48/kg

               RA 500M - £18.14/kg

 

 

For comparison, we have just put on 5 coats of the jotamastic 90 (onto the boat, not ourselves). Prices available online.

Edited June 24, 2023 by rusty69

[system 4-50]

27 minutes ago, rusty69 said:

we have just put on 5 coats of the jotamastic 90 (onto the boat, not ourselves)

Your bottom will not last as long...

[rusty69]

2 minutes ago, system 4-50 said:

Your bottom will not last as long...

S'ok. I know where there is some green paint going cheap.

[blackrose]

2 hours ago, rusty69 said:

 

When I contacted chemco, their commercial coordinator advised me of the following. He mentioned nothing about mixing with water, or applying in the rain:

 

All existing coating must be removed and bare steel exposed
Surface to be cleaned and free from all contaminations including oil and grease
Surface to be prepared to minimum St2 – but more optimal surface preparation increases life expectancy of system (such as WJ2 / St3)
Apply one coat of RS 500P at 100 microns
Apply two coats of RA 500M at 250 microns each (500 microns total)
Corners, edges, and weld areas to be stripe coated with same coatings
Surface must be fully cured before being put into service

 

They do not appear to be vastly different from the jotamastic 90 that I ended up using.

 

At the time I requested a quote from chemco, their costs were:

 

For 50m² surface area you’ll require minimum:

 

RS 500P – 10kg

RA 500M – 40kg (20kg per coat)

 

Pricing (ex-works) is as follows:

               RS 500P – £15.48/kg

               RA 500M - £18.14/kg

 

 

For comparison, we have just put on 5 coats of the jotamastic 90 (onto the boat, not ourselves). Prices available online.

 

No paint system can be applied to poorly prepared substrates in atrocious weather conditions and be expected to last, I'm afraid that's just fantasy. The Jotamastic you've used is about as surface tolerant as they come. 

Edited June 24, 2023 by blackrose

[Bargebuilder]

6 minutes ago, blackrose said:

 

No paint system can be applied to poorly prepared substrates in atrocious weather conditions and be expected to last, I'm afraid that's just fantasy. The Jotamastic you've used is about as surface tolerant at they come. 

I would have agreed 100% had I not watched the Chemco product be applied to wet, gingered steel in the rain and then monitored it's performance over the following three years. A single coat held perfectly without any top coat.

 

The other advantage of the Chemco system is the minute platelets of glass that are included in the coating, which lay against the steel plate forming a very hard layer which is highly resistant to abrasion and only easily removable with an angle grinder and grinding disc if you get it wrong!

 

Back in 2011 I bought and applied by roller 80kg, 2 coats of RS500P and 5 coats of RA500M, so not only can I state from first hand experience that it performs superbly and is highly scratch and scrape resistant, but also that it is very easy to apply by ordinary roller, so no need for an airless sprayer.

 

I should also mention that my barge is coastal and moored on a salt marsh, a salt water environment that is probably much harsher than fresh water. 

 

I'm sure the Jotamastic will be fine and in 5 years Rusty69 will confirm this to be the case, but I can vouch now from first hand experience that the Chemco system is excellent, having applied it to my barge 12 years ago with no sign anywhere of failure or corrosion.