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Epoxy over bitumen


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7 hours ago, blackrose said:

 

I'm a bit confused. Any epoxy can go over itself? Either overcoat within the maximum overcoating time as specified in the TDS or key with an appropriate grit paper and recoat. 

 

If you've found an epoxy that can go over bitumen and does what you need it to do then good luck to you. However, I would have thought that at some point you will need to get the whole lot off and that might be a pain. But let us know how it goes.

As in a different type of epoxy with different characteristics. I'm just quoting SML.

9 hours ago, Bod said:

B/F

Do you have a link to the product you intend to use?

I would be interested in seeing the data sheets for this.

 

Bod

It's linked on the OP, scroll down the product page.

6 hours ago, Dr Bob said:

There are 2 types of coatings. Barrier and passive. Epoxies are barrier. They work by stopping water and oxygen getting to the surface BUT they must have excellent adhesion to the substrate ( i.e. Steel). That stops undercutting and rust penetration under the coating. They will not work well if applied over a soft single pack with poor adhesion i.e. Blacking.

Now if the OP has found some super duper snake oil type modified epoxy that will work as a barrier over soft coatings then let's see the data sheets. In 40 years since being in the epoxy formulation game, none of the big boys have EVER achieved this!

Trust me, I'm a doctor.

Data sheets on the product page linked on the OP.

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6 hours ago, Dr Bob said:

SML a big hitter in the marine coatings market. Er, no. International, Jotun, Hempel......yes!

They're the main UK distributer for Jotun and are saying it's suitable for topcoating with Jotun etc, so I'm presuming they're fairly confident about its performance, it'd be very bad for a reputable company to tout a crap product that's going to cause loads of bad press down the line. Or one would presume so. New and game changing products do get invented, we'd all be cruising in reed coracles if they didn't.

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7 hours ago, blackrose said:

 

I'm a bit confused. Any epoxy can go over itself? Either overcoat within the maximum overcoating time as specified in the TDS or key with an appropriate grit paper and recoat. 

 

If you've found an epoxy that can go over bitumen and does what you need it to do then good luck to you. However, I would have thought that at some point you will need to get the whole lot off and that might be a pain. But let us know how it goes.

As I said I was dubious and still am, but it cost me less than £200 more than a standard blacking job including the base plate and we all know bitumen melts when it gets oil and diesel on it so I thought I would give it a try, next year I may do the same of maybe I will go back to bitumen, depends what it looks like. I think you will find that is what they are doing at Ellsmere museum now. 

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48 minutes ago, barmyfluid said:

As in a different type of epoxy with different characteristics. I'm just quoting SML.

It's linked on the OP, scroll down the product page.

Data sheets on the product page linked on the OP.

 

Who actually makes the product? If I still had bitumen on my hull I'd probably give this stuff a go, but I don't think I'd waste my money putting Jotamastic 87 over the top if that's the idea. I notice on the data sheet under typical applications that SML are saying it's a high-build epoxy undercoat for upgrading several existing paint systems, but they neglect to mention what they're designed to be upgraded to. 

 

Edited by blackrose
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15 minutes ago, blackrose said:

 

Who actually makes the product? If I still had bitumen on my hull I'd probably give this stuff a go, but I don't think I'd waste my money putting Jotamastic 87 over the top if that's the idea. I notice on the data sheet under typical applications that SML are saying it's a high-build epoxy undercoat for upgrading several existing paint systems, but they neglect to mention what it's designed to be upgraded to. 

 

Dunno who makes it, and it's not very clear about use for NB blacking TBH, I exchanged a few emails with SML before I found out. Although it's billed as an undercoat, a topcoat is only essential to stop it chalking, and for below waterline use you can use it on its own, and they recommended 'at least 2 good coats', so I was planning 2 and another at the waterline. It doesn't have to be perfect or as good as a shotblast job, it just needs to be better than bitumen, and at the waterline that's next to useless after a few slicks, ice etc.

 

Upgrading from bitumen etc to an epoxy based one.

Edited by barmyfluid
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23 minutes ago, barmyfluid said:

Dunno who makes it, and it's not very clear about use for NB blacking TBH, I exchanged a few emails with SML before I found out. Although it's billed as an undercoat, a topcoat is only essential to stop it chalking, and for below waterline use you can use it on its own, and they recommended 'at least 2 good coats', so I was planning 2 and another at the waterline. It doesn't have to be perfect or as good as a shotblast job, it just needs to be better than bitumen, and at the waterline that's next to useless after a few slicks, ice etc.

 

Upgrading from bitumen etc to an epoxy based one.

 

It doesn't say that in the data sheet, that's just what you're telling us. My point was that the data sheet is vague on what users are supposed to upgrade to.

 

You'll get chalking anyway with Jotamastic 87 - have a look at the data sheet that I posted. I've got 4 coats of Jotamastic 87 on my hull and it turned from black to grey but chalking doesn't affect the coating's performance. If you want Jotamastic 87 to stay black you have to overcoat with Jotamastic Hardtop. So as far as I can see there's absolutely no point in over coating the Ballistic epoxy with Jotamastic 87. Just prep what you've got on your hull according to the data sheet and put at least two coats of Ballistic over the top, preferably more, paying strict attention to the mixing instructions and overcoating times.  

 

The fact that we don't know who makes Ballistic epoxy would concern me if I was considering using it. I'd like to know what the results are like in a few years time. If it's good and it increases the periods between dry-dockings then I'm sure others on here will be interested too.

Edited by blackrose
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Just now, blackrose said:

 

It doesn't say that in the data sheet, that's just what you're telling us. My point was that the data sheet is vague on what users are supposed to upgrade to.

 

By itself the product is a 2 pack epoxy coating, it's called 'Ballastic epoxy' and it's implied you understand what this is; as I said, I had to email SML before finding out using it on it's own was fine, that is 'the upgrade'. If you want it from the horses mouth or are unsure of something, email SML.

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15 minutes ago, barmyfluid said:

By itself the product is a 2 pack epoxy coating, it's called 'Ballastic epoxy' and it's implied you understand what this is; as I said, I had to email SML before finding out using it on it's own was fine, that is 'the upgrade'. If you want it from the horses mouth or are unsure of something, email SML.

 

I'm fully aware that the product is a two pack epoxy, but what you don't seem to understand is that doesn't necessarily mean it's compatible with all other two pack epoxies on the market which might go over the top of it. Also the product data sheet describes it as an undercoat, therefore it's reasonable to assume that it's designed to go under something else. It says nothing about being ok to use on its own on SML's own data sheet. 

 

The other thing you don't seem to understand is that SML are just a supplier, they're not a paint manufacturer - therefore they not the horse's mouth!

 

Listen, as an experienced user of two-pack epoxies I'm just trying to help you as were others on this thread. However, if you're determined not to listen to anyone (apart from SML) then it's your boat so do what you want and good luck to you. 

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28 minutes ago, blackrose said:

 Also the product data sheet describes it as an undercoat, therefore it's reasonable to assume that it's designed to go under something else. It says nothing about being ok to use on its own on SML's own data sheet. 

As I mentioned several times in this thread, it was unclear on the datasheet (which is letterheaded as SML, so that's as close to the horses mouth as I can find, if you know better, please share) as to what it's supposed to go under. It's vague at best. So I emailed SML for further information, and (again, as I've mentioned several times), they informed me that it is in fact fine as a single coating, or can be overcoated with other epoxies, such as Jotun topcoats. I don't understand your problem.

 

I've listened to everyone on this thread, and agree with most, I'm certainly dubious about a new product that aims to sidestep a big cost ('"sounds too good to be true"), but I've explained why I think (or hope) it may be ok and worth a punt.

 

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58 minutes ago, blackrose said:

it's your boat so do what you want and good luck to you. 

 

Yep, but please let us know how well it works, as there would be many boaters interested in how well it works.

 

My personal preference is jetwash, hard scrape back to steel, cup brush on an angle grinder then apply two pack.  It's not shotblast to Swedish standard 2.5, but as @dmr commented earlier no coating can survive point impact between boat and concrete anyway so I two pack every 2 or 3 years.

 

Firwoods used to do a wonderful coal tar  2 pack that was designed for slurry tanks and water reservoirs, but it had too much of the good stuff in it so got banned under the environmental regulations.  Stayed semi-soft, so reflowed over scrapes on a hot day and self healed.  I'd still be using it if they still made it!

 

Switched to Hempel Hempadur last year using the same technique, and it's stayed on where it's not been scraped off!  With hindsight, two pack blacking in April in Wigan followed by the BCN Challenge in May wasn't the best idea ...

 

 

 

Edited by TheBiscuits
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42 minutes ago, TheBiscuits said:

 

Yep, but please let us know how well it works, as there would be many boaters interested in how well it works.

 

 

But if it works to our satisfaction no one on here will believe us, so a bit pointless

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14 minutes ago, ditchcrawler said:

But if it works to our satisfaction no one on here will believe us, so a bit pointless

 

Lol, funny how 'watching paint dry' a simile for boring but suggesting a new product is grounds for rage and cries of heresy.

 

When she could no longer hide him, she took a papyrus basket for him, and coated it with tar and with pitch. 

She put the child in it, and laid it in the reeds by the river's bank

Exodus 2

 

Oh, it was good in the time of Moses, it's good enough for me.........

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1 hour ago, barmyfluid said:

As I mentioned several times in this thread, it was unclear on the datasheet (which is letterheaded as SML, so that's as close to the horses mouth as I can find, if you know better, please share) as to what it's supposed to go under. It's vague at best. So I emailed SML for further information, and (again, as I've mentioned several times), they informed me that it is in fact fine as a single coating, or can be overcoated with other epoxies, such as Jotun topcoats. I don't understand your problem.

 

I've listened to everyone on this thread, and agree with most, I'm certainly dubious about a new product that aims to sidestep a big cost ('"sounds too good to be true"), but I've explained why I think (or hope) it may be ok and worth a punt.

 

SML are not a major player in the formulation of epoxy coatings. They may be an agent for Jotun but that does not mean they know how well epoxies work. There has not been ANY miraculous breakthrough in the last  5 years that allows epoxies to be applied over soft coatings and perform the same as properly applied epoxies. If there was, do you not think that Jotun, Hemel and international would be touting it? It's a small company pushing their version of snake oil.

SMLs blurb says "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."

No, it does not have 'all the protection of an epoxy primer'  - unless it is applied over an SA 2.5 surface. That statement is toatally misleading. You do not understand epoxy coatings. The MSDS sheet suggests this is just a bog standard epichlorhydrin based epoxy - no sexy modifications - so it aint goin' to be any thing different.

As a guy who spent years formulating epoxies...I do. I could give you chapter and verse over why you cant apply them over a soft bitumen coating, but as you wont listen to Blackrose, it is not worth my time bothering.

Dont waste your money. It may give you a few years more lifetime than blacking but at £60 for 5L (and the thickness you need to put it on at), it just aint worth it.

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8 minutes ago, Dr Bob said:

SML are not a major player in the formulation of epoxy coatings. They may be an agent for Jotun but that does not mean they know how well epoxies work. There has not been ANY miraculous breakthrough in the last  5 years that allows epoxies to be applied over soft coatings and perform the same as properly applied epoxies. If there was, do you not think that Jotun, Hemel and international would be touting it? It's a small company pushing their version of snake oil.

SMLs blurb says "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."

No, it does not have 'all the protection of an epoxy primer'  - unless it is applied over an SA 2.5 surface. That statement is toatally misleading. You do not understand epoxy coatings. The MSDS sheet suggests this is just a bog standard epichlorhydrin based epoxy - no sexy modifications - so it aint goin' to be any thing different.

As a guy who spent years formulating epoxies...I do. I could give you chapter and verse over why you cant apply them over a soft bitumen coating, but as you wont listen to Blackrose, it is not worth my time bothering.

Dont waste your money. It may give you a few years more lifetime than blacking but at £60 for 5L (and the thickness you need to put it on at), it just aint worth it.

Thank you for your opinion and input, it's appreciated. Not sure what I'm not listening to Blackrose about as they said "If I still had bitumen on my hull I'd probably give this stuff a go", the rest appears to be repeated questions about usage I'd already answered until it got a bit sniffy. I've also, repeatedly, said I think it probably wouldn't be as good as a shotblast job but be a bit better than bitumen, I don't see why you think I'm not listening or disagreeing with consensus, or what you just said. Well, I do, because I know that nobody actually bothers reading posts, they just scan for word combinations that make them angry then fire off. Honestly, the internet..... 

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4 minutes ago, matty40s said:

...well if you insist on doing the Walsall

 

 

.

The only real problem with the Walsall is an unbelievable amount of weed and water-lilies, because nobody uses it.  These will not damage epoxy ?. Having now done the Manchester Rochdale several times I dream of doing the Walsall again ? (and a fine pub as a reward)

 

................Dave

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13 hours ago, barmyfluid said:

 

Lol, funny how 'watching paint dry' a simile for boring but suggesting a new product is grounds for rage and cries of heresy.

 

When she could no longer hide him, she took a papyrus basket for him, and coated it with tar and with pitch. 

She put the child in it, and laid it in the reeds by the river's bank

Exodus 2

 

Oh, it was good in the time of Moses, it's good enough for me.........

Yeaar, right -

 But Moses wasn't subjected to scraping along a concrete sided channel, or in mucky waters or an abrasive bottom....

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Having read the Data sheet, the spray application is a definite shot blast prep, the brush/roller application is a removal of all loose coatings and feathering of all edges, and gives a standard of prep required.

Also lists "Compatable with most aged existing coatings" which will give them an excuse for poor adhesion.  Either you did not remove all loose coating, or well it must be incompatible with what you have put on before.

Please let us know what you decide, and how the Ballistic epoxy wears if you use it.

 

Bod.

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8 minutes ago, OldGoat said:

Yeaar, right -

 But Moses wasn't subjected to scraping along a concrete sided channel, or in mucky waters or an abrasive bottom....

Oooh I don't know, was down the Nile the other day, got chafed by a crocodile, t-boned by a hire dhow and rammed a block of pyramid stone that was on the bank. 

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The issue with bitumen I think is mainly around the waterline. Maybe it is worth seriously preping 3" either side of the waterline and trying this stuff on it. I have found that a couple of coats of a zinc based primer makes quite a difference to the rate of rusting at the waterline as the first diesel spill tends to wash it off with a bit of wind or flow on the water. I am sure nothing can bond to bitumen except more bitumen and its a pretty good release agent. 2 pack is great coating but only after proper shot blasting.

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4 minutes ago, barmyfluid said:

Oooh I don't know, was down the Nile the other day, got chafed by a crocodile, t-boned by a hire dhow and rammed a block of pyramid stone that was on the bank. 

Oh dear how times have changed  - perhaps we need a new edition of the Old Testament......

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10 minutes ago, Bod said:

Having read the Data sheet, the spray application is a definite shot blast prep, the brush/roller application is a removal of all loose coatings and feathering of all edges, and gives a standard of prep required.

Also lists "Compatable with most aged existing coatings" which will give them an excuse for poor adhesion.  Either you did not remove all loose coating, or well it must be incompatible with what you have put on before.

Please let us know what you decide, and how the Ballistic epoxy wears if you use it.

 

Bod.

I was planning on cup brushing the waterline at least, I think that's the main area where it stands a chance of being worth the extra cost over standard. I had rust spots with bitumen (Hempel) within 8 months previously, I'll certainly report back, many people are interested.

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8 minutes ago, Mike Adams said:

The issue with bitumen I think is mainly around the waterline. Maybe it is worth seriously preping 3" either side of the waterline and trying this stuff on it. I have found that a couple of coats of a zinc based primer makes quite a difference to the rate of rusting at the waterline as the first diesel spill tends to wash it off with a bit of wind or flow on the water. I am sure nothing can bond to bitumen except more bitumen and its a pretty good release agent. 2 pack is great coating but only after proper shot blasting.

Hah, just mentioned that - yes, definitely. I'd often wondered if there wouldn't be some sort of sealant that would work to some degree over bitumen to give it solvent resistance at the waterline, something like a spray varnish.

 

I'm sure I've heard people say that a 'paint job' is as good or better than blacking, and I've seen some odd looking waterlines going by from time to time.

Edited by barmyfluid
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