Widebeam Hull Blacking

[Guest]

Hi we have just brought a widebeam boat that is 3 years old but a lot of information is missing we are not sure whether the hull is already blacked in 2 pack epoxy or bitumen is there a way of knowing the difference via a test as we want to put the best epoxy on the hull but unclear what the previous paint was and know that epoxy cant be put onto bitumen

 

does anyone know how to test this

 

thanks 

[stegra]

2 pack will be rock hard, like set paint. Bitumen will be softer so can be scraped off. If you dampen a rag with white spirits it will remove the surface layer of bitumen whereas 2 pack won't be affected. 

[Horace42]

1 hour ago, Jen011 said:

Hi we have just brought a widebeam boat that is 3 years old but a lot of information is missing we are not sure whether the hull is already blacked in 2 pack epoxy or bitumen is there a way of knowing the difference via a test as we want to put the best epoxy on the hull but unclear what the previous paint was and know that epoxy cant be put onto bitumen

 

does anyone know how to test this

 

thanks 

Stegra is right.

If it is bitumen and you want 2-pack epoxy you are likely to need it shot blasted back to bare metal.  I am not sure about new epoxy on old epoxy.

[Guest]

7 hours ago, stegra said:

2 pack will be rock hard, like set paint. Bitumen will be softer so can be scraped off. If you dampen a rag with white spirits it will remove the surface layer of bitumen whereas 2 pack won't be affected. 

Hi thanks very much it is very hard and not soft at all I will get some white spirit on a rag today and see it anything comes off, so to confirm if nothing comes off the blacking it is epoxy ?  I know there is no way you can scrape off the paint it is rock hard and not soft at all thanks so much for your advice with this as the paints are very expensive and the last thing we want to do is get the paint wrong from the start !!

 

5 hours ago, Horace42 said:

Stegra is right.

If it is bitumen and you want 2-pack epoxy you are likely to need it shot blasted back to bare metal.  I am not sure about new epoxy on old epoxy.

 

[ditchcrawler]

If you are confident its epoxy after the Spirit test I would suggest try sanding a small spot with sand paper, it should feel like a very hard gloss paint and come off in a fine dust.

[Guest]

Hi Brian thanks, we are a bit confused with it all as we have done the spirit test and there is some black on the cloth we have done this a few times so now concerned that it may well have another coating on it, will try the sanding test but someone suggesting putting some 2 pack epoxy primer on the hull in a small section and if the primer reacts and bubbles then it is not epoxy underneath, would anyone know if that is correct.  There are quite a few people that have looked at the boat and all think it is epoxy.

 

I have managed to find a picture of the boat when it was originally built and this is the coating that is still on it if that helps and a close up of the hull as it is 

 

thanks everyone for your advice this is really appreciated

[peterboat]

Whatever it is it looks sprayed, who built the boat? and if you find that out ask them what they put on it, It looks like its still original so you have a chance of getting info that way. Good luck with your mission

[system 4-50]

If it is epoxy then it will have been on since new.  Have you asked the builder?

[dmr]

It looks like a brand new boat, has it ever been in the water?

 

As said, speak to the builder if you can. Trouble is you don't know how well that epoxy was put on (or what it is), it might have gone on to new steel with millscale rather than shotblasting.  Might be best to use the boat for a couple of years to see how the stuff stays on, then decide between more coats or a shotblast and start again. Epoxy is not cheap so would be sad to put new stuff over a bad job.

 

If boat has never been in water then  it might be just a "holding cut" of grey oxide primer, that's what it looks a bit like to me in the top photo..

 

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

[Guest]

Hi Dave, yes it is 3 years old but has never been in the water you are correct sorry should of mentioned that.

 

So we are at a stage now where we have brought the boat from a previous owner who was going to fit it out then didn't and he had brought it from the person before who is no longer contactable who brought it from new.

It has sat in the same boat yard for 3 years and has never been in the water.

 

I am hoping it is primer as it looks very thin not thick at all the problem I have is that the boat builder is not contactable due to being away for summer and this is stopping us from progressing with the hull as ideally we want to protect it before winter even if we cant do the fit out before then.

 

Is it possible to put 2 pack epoxy on grey oxide primer do you know and how do we know if that is in fact what it is is there any test for that.

 

I am sure I will have so many more questions and am glad I joined this forum as our dream is to live in this boat on the canals so it is so important to us that we dont make a mistake as you said the 2 pack expoxy paint is very very expensive so it would be a massive mistake if wrong.  I am also thinking the worst case scenario would be that if we was to put bitumen on it and have it taken out every 3 years and repaint it surely that would be good enough anyway am not entirely sure what the point of expoxy is other than to prolong the life in the water however you still have to change the anodes I would guess and maintain the boat and I am not sure I would want it sitting for 7 years with no hull maintenance if you see what I mean but I could be wrong.

Thanks 

 

Jen

[dmr]

57 minutes ago, Jen011 said:

Hi Dave, yes it is 3 years old but has never been in the water you are correct sorry should of mentioned that.

 

So we are at a stage now where we have brought the boat from a previous owner who was going to fit it out then didn't and he had brought it from the person before who is no longer contactable who brought it from new.

It has sat in the same boat yard for 3 years and has never been in the water.

 

I am hoping it is primer as it looks very thin not thick at all the problem I have is that the boat builder is not contactable due to being away for summer and this is stopping us from progressing with the hull as ideally we want to protect it before winter even if we cant do the fit out before then.

 

Is it possible to put 2 pack epoxy on grey oxide primer do you know and how do we know if that is in fact what it is is there any test for that.

 

I am sure I will have so many more questions and am glad I joined this forum as our dream is to live in this boat on the canals so it is so important to us that we dont make a mistake as you said the 2 pack expoxy paint is very very expensive so it would be a massive mistake if wrong.  I am also thinking the worst case scenario would be that if we was to put bitumen on it and have it taken out every 3 years and repaint it surely that would be good enough anyway am not entirely sure what the point of expoxy is other than to prolong the life in the water however you still have to change the anodes I would guess and maintain the boat and I am not sure I would want it sitting for 7 years with no hull maintenance if you see what I mean but I could be wrong.

Thanks 

 

Jen

Its a difficult one, if that's primer then ideally it should come off, blacking is designed to stick to bare metal. I think your two best options are either to shotblast and epoxy now, or just stick some bitumen on top of what you have now and decide what to do next time its out of the water in 2 or 3 years time.

 

Anodes often don't need replacing that often, and if the boat is done in epoxy then they might last many many years. Epoxy sticks on and protects the boat much much better than blacking, after three years it will have a few scrapes, or still be pristine if your boat is a non moving residence, whilst blacking will likely show bubbling rust all round the waterline.  Epoxy is pretty new in the narrowboat world, most boats are still done in conventional blacking and last for ages, in fact if you do nothing at all and leave the boat in bare metal I suspect it will still likely last for 20 years. Personally I much prefer epoxy.

 

 

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

Edited July 3, 2018 by dmr
trivial

[ditchcrawler]

If its 3 years old and faded to a shade of grey that is another indication its epoxy, it does fade

[David Mack]

And assuming you want to paint the topsides as well, if the boat has sat in grey primer for three years, that will need a good going over to remove any loose paint and rust. Primer alone is not waterproof, so it is likely that the rust will have got under it in places.  In your top picture the bottom edge of the rubbing strip looks rusty.

[WotEver]

33 minutes ago, David Mack said:

In your top picture the bottom edge of the rubbing strip looks rusty.

As does the top edge, albeit not as bad. 

[Bee]

Its tricky innit. I think Epoxy is superior, I think most would agree. Some epoxy paint is 'surface tolerant' Look at Jotun paints for example, see Jotun 35 (37)? and might not need shotblasting . Existing epoxy should, I think, be at least sanded to provide a key. Look at great big sea going ships, they do not always get shotblasted every few years. Old fashioned bitumen paint has really had its day and (I think) might be banned soon, it is in Holland and I think it will be here too. But, there are other options, Ballistic black could be worth looking at, I've never used it but worth getting some advice from the makers. Also, if you haul the boat out every 3 years or so I think you could use B&Q white gloss and it would be ok, I exaggerate but you get the idea. So, probably not much help but maybe a bit more info.

[Guest]

Hi thanks for your replies we are still none the wiser though after the tests I think we are now going down the lines of having the whole boat sandblasted and start from fresh that way we know what we are putting on and can sort the rust out in the meantime.  The boat is new but unfortunately has been sitting near the sea for 3 years on hard standing so has got a lot of surface rust and maybe more under the paint that we cant see and we was just talking about it may be the cleanest and easier option to get this ready for primer and probably epoxy for the hull 

 

a big job though as it is 60 ft !!

[matty40s]

4 hours ago, Jen011 said:

Hi Brian thanks, we are a bit confused with it all as we have done the spirit test and there is some black on the cloth we have done this a few times so now concerned that it may well have another coating on it, will try the sanding test but someone suggesting putting some 2 pack epoxy primer on the hull in a small section and if the primer reacts and bubbles then it is not epoxy underneath, would anyone know if that is correct.  There are quite a few people that have looked at the boat and all think it is epoxy.

 

I have managed to find a picture of the boat when it was originally built and this is the coating that is still on it if that helps and a close up of the hull as it is 

 

thanks everyone for your advice this is really appreciated

Looks a bit like a Collingwood,  if it is, check the bow thruster tube, it almost certainly won't have been blacked,  no new ones lifted in that I have seen for the last couple of years have been.

Today's one....

 

[Guest]

Hi all another question if we was to strip the boat to bare metal (sandblaster) would it be a good idea to put red oxide paint on the metal before a 2 pack primer in anyones opinion 

 

thanks

[rusty69]

2 minutes ago, Jen011 said:

Hi all another question if we was to strip the boat to bare metal (sandblaster) would it be a good idea to put red oxide paint on the metal before a 2 pack primer in anyones opinion 

 

thanks

No

[ditchcrawler]

14 minutes ago, rusty69 said:

No

Thats a definite No. Follow the paint manufacturers instructions to the letter, temperature, humidity, steel temperature and preparation.

[stegra]

If you do get it shot blasted, it will start to oxidise (rust) literally overnight. You will need to fully prepared to get the first coats on immediately. Leave it for a couple of days, even without rain, and it will take on an orange hue. 

[ditchcrawler]

4 minutes ago, stegra said:

If you do get it shot blasted, it will start to oxidise (rust) literally overnight. You will need to fully prepared to get the first coats on immediately. Leave it for a couple of days, even without rain, and it will take on an orange hue. 

We use to blast in the morning and paint in the afternoon.

[WotEver]

27 minutes ago, ditchcrawler said:

We use to blast in the morning and paint in the afternoon.

Best to do it in the next 10 days while we have the weather...

 

[system 4-50]

41 minutes ago, stegra said:

If you do get it shot blasted, it will start to oxidise (rust) literally overnight. You will need to fully prepared to get the first coats on immediately. Leave it for a couple of days, even without rain, and it will take on an orange hue. 

Jotamastic 87 specifies that a little flash rust is not a problem.

[Dr Bob]

1 hour ago, system 4-50 said:

Jotamastic 87 specifies that a little flash rust is not a problem.

But it will be better with no rust. Blast to SA 2.5 for best performance. To me those pics look like it had a few coats of primer when new so best blast them off and get a 2 pack epoxy on and no oxide primer!