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Blacking or epoxy coating?


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Lizzy,

We 'blacked' our hull this year, - similar process to yours really - - sandblast, chemical wash, then a two-pack Jotamastic 87 primer, followed by two coats of Jotamastic 87.

We'd booked a dry dock and did the job myself - (because I really wanted to discover the condition of the hull in the first place, and then make sure that the job met the process spec's of the paint). We let it cure for a week before refloating.

I can say that the paint was well on it's way to being very hard indeed, and that yours really should be the same. I reckon Dr Bob's observations above are absolutely spot-on, and they would be an ideal route to start the discussions for remediation by the boatyard.

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@Dr Bob Thank you so much for your advice. It is so helpful to take the subjectivity out of it between the boatyard saying don't bash into things and me saying I didn't do it!

 

Here are two videos and one photo:

- Making a hole with a scraper. The epoxy did not splinter but rather curl. The curl is harder than cheese I would say, but crumbly.

- Video from scratching it with my fingernail. The scratch is a lighter colour, which I believe is the primer underneath.

- The picture is from scratch marks from the curvy bit at the stern, which really doesn't get a lot of impact at all. Not sure where I scraped this but it can't have been hard.

 

Would love to hear your view. It's not so easy to video this up close so I hope it shows up OK. Thank you so much for your help!

image1.jpeg

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1 minute ago, rusty69 said:

Oh.Its probably a problem at my end then.

 

The file downloads,an single image is displayed and the video forwards to the end, using VLC player.

It's a .mov file (iphone video). Maybe this isn't the right player for it?

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9 minutes ago, WotEver said:

The videos play fine on my phone and VLC should have no problems on a pc. 

 

Back to the OP... that paint is definitely faulty. I’ll let the good doctor suggest the cause. 

Standard Windows programs don't support it, you need something like VLC to see it

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42 minutes ago, Lizzy said:

OK I managed to convert the two videos to mp4 format. Eagerly awaiting Dr. Bob's verdict. I have written to Hempel as well. They were very responsive and came back asking for exact conditions etc. I sent them the fingernail video too. I am a bit more hopeful now.

 

 

 

 

 

 

Lizzy,

None of the videos run on my mac or ipads but the mp4s did play on my android phone - success.

I cant really tell from the shots but your finger nail shouldnt be making that mark after  2 weeks. Let me know what date they finished the paint job. On  the video with the scraper, you need to scratch the surface. Push the scrapper in one direction and try and curl the coating like you would do butter. Try and do a 2 " scrape. Yes it will damage the coating but you have to do that to test it. Try and get it on video. If the paint curls round like butter it is very clear then it is not cured.

This is exactly what the Hempel tech guy will do. If you do find it cheesey via this test, then repeat at 4 places around the boat to see how widespread the problem is and on both sides if the sun has been more on one side as I said in the previous email. To me at the moment, it looks like it might be under cured but not enough evidence yet to jump up and down on the boatyard. Try and do the test today/tomorrow...but rain forecast tomorrow. Keep Hempel advised on what you are doing and say you are going to get more videos to try and confirm the softness. Say if you confirm the softness with the pen knife test you will ask  them to come and look as there wil be a £2-5K claim against either the boatyard or Hempel. Hempel will bend over backwards to show it wasnt them.

Where is the boat?

If it is soft (the technical word is cheesey!) then that could be down to a number of causes. It could be a bad batch from Hempel - that's why they will be keen to jump in to clear their name. A bad batch could arise from a number of things. Then it could be the application. Poor mixing of the 2 pack, too much sovent added as a thinner, the wrong solvent added as a thinner, too low a temperature. Maybe water between coats but I doubt that. Etc Etc. The thing is, if you can prove it is cheesey then you have a claim against the boatyard. A paint expert will be able to tell from the pen knife test if it was a problem affecting all coats or just one of them. There may be other visual evidence of the problem..viz orange peel, aligatoring, paint runs, colour etc which a paint expert will pick up from the examination. I think Hempel will be your friend here. I can help remotely. If it really is cheesey, it may be worth getting your own expert to inspect it and write a report.

First up though, before you worry about what has gone wrong and how to fix it, do the pen knife test over 4 points on the hull and report back. If you do get a 'curl' then photo that curl as that will be very conclusive something is badly wrong.

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Two videos from two places (bow and stern) spliced into one. This is the side that got a bit less sun probably. The other side is the canal, I didn't quite manage to scrape and video it hanging over the water. I did try a spot there, no discernible difference I would say.

 

I would say it curls. Would you? Sorry I didn't have it in myself to make a 2 inch strip. Just too painful to scrape it all off! I hope this is enough for you to see.

 

The second coat was applied 21st Sep. The boat is in West London. If you are anywhere near I'd be forever grateful for a personal assessment. Would be happy to pay expenses too.

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3 minutes ago, rusty69 said:

The last coat went on 21st Sept, and the boat was refloated on what date? I think you mentioned last week

Boat was refloated 27th. But this is all above the waterline anyway. The deep scratches I got from usage are all from 29th. I will be travelling on tomorrow through 3 more locks. I will see how that goes, but I don't have the feeling that it has hardened much more since last week.

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1 minute ago, Lizzy said:

Boat was refloated 27th. But this is all above the waterline anyway. The deep scratches I got from usage are all from 29th. I will be travelling on tomorrow through 3 more locks. I will see how that goes, but I don't have the feeling that it has hardened much more since last week.

Ah, yes of course.I await Dr Bob, but 21-27,unless average temperature was high doesn't  sound particularily long. Not sure what the product data sheet says, but worth arming yourself with that aswell.

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5 minutes ago, WotEver said:

I would. Bob?

Yes I agree Tony.

Lizzy, It is not as soft as I thought it would be but that is too soft for 14 days.

I would formulate and send a formal email to Hempel and the yard and include that video and say you are not happy with the paint job, in that the 2 pack epoxy has not cured as demonstrated by the pen knife test in the video. Ask them to come out to inspect the boat at their earliest convenience and send you a copy of that inspection report., and then for them both to propose how to rectify the problem. Keep a copy of all correspondence in case it does go to litigation. Do that, and then lets see how the boatyard and hempel respond. There is not a lot you can do at the moment. The best outcome in the next week is that hempel come out and inspect the boat. Their report should identify the extent of the problem.

7 minutes ago, rusty69 said:

Ah, yes of course.I await Dr Bob, but 21-27,unless average temperature was high doesn't  sound particularily long. Not sure what the product data sheet says, but worth arming yourself with that aswell.

6 days curing before putting back in the water is probably ok. Lizzy, what coating was it that was applied? Hempadur XXX?? Some of the hempadur range say 7 days to full cure at 20°C. Of course it has not been 20 but in a week, the solvent will have evaporated hence cure will continue over weeks and months. The problem here is that the bit above the water is not cured well enough and may never reach full cure so will not work as advertised.

Lizzy, not sure I can make London as I am up in Brum. See what Hempel come back with. If there is a big argument you will need your own paint expert.

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