DIY Hull Grit Blasting

[bag 'o' bones]

Has anyone on here ever hired the necessary kit and done the job themselves?

 

If so, was it worth it, or with hindsight would you have hired a pro?

[Bobbybass]

Tried it.

 

Dusty..nasty...goes everywhere...and when that grit lands on other stuff even the slightest attempt to rub it off scratches windows..paint...peoples cars etc..

 

Wished..I hadn't tried it !!

[sueb]

There is a wet grit system that is supposed to be better.

Quill grit blasting will find it. I've only seen it demonstrated

[SamKingfisher]

Anyone tried ice blasting?

[Grace and Favour]

Anyone tried ice blasting?

Or Bicarbonate blasting

 

 

 

 

(I would imagine wet/ice blasting will encourage surface rust to form very quickly)

[Chagall]

Hire the pro....its worth it! but even with all the windows, gaps etc sealed up, the grit got in, and seeing how they do it, its not an easy job! I was surprised by how powerful the stuff can be at the sort of pressure its applied... and you need to be able to get the primer on within, at the very least, four hours....

[BEngo]

Has anyone on here ever hired the necessary kit and done the job themselves?

 

If so, was it worth it, or with hindsight would you have hired a pro?

Hire a pro.

 

Even if you could hire the right sort of kit, selecting the grit, the pressure and the nozzle is a skilled art. Using it is not easy either and it's quite simple to cause serious injury with grit that can be travelling at over 400mph. Do you know what the various grades of blasted steel look like- you will need to achieve at least SA 21/2 to keep the paint makers happy and get full value out of it.

 

As well as a blasting pot, nozzle and protective gear you will need a serious compressor- something with a 70-80HP engine is about right if you want to do a 50- 60ft boat in one day ( blast and first coat).

 

N

Edited March 6, 2014 by BEngo

[Ex- Member]

We looked in to hiring all the kit, it's very expensive and would only have saved a few quid by the time you take into account you also need to hire a vehicle with tow bar to tow the compressor hire a flat bed for the blast medium and blaster it's self. I recall pricing it all up with my brother as we planned to do both his and our boats, I recall the costs were around £500 but that was 5 years ago and then you have to do the job yourself.

 

I recently got an excellent shot blaster to do our wide beam hull, it took him just 5 hours and cost £400 which included the base plate.

 

Shop around and you will get a decent price. I personally wouldn't pay more than £500 We had several quotes when we got ours done last year from £350 from the company that did the job to £2,000

 

We did have 2 other reasonable quotes one for £500 and one for £550 So it is possible to get it done at a reasonable cost.

 

Avoid larger companies as they will charge v.a.t.

Edited March 6, 2014 by Julynian

[Androo]

Tried it.

 

Dusty..nasty...goes everywhere...and when that grit lands on other stuff even the slightest attempt to rub it off scratches windows..paint...peoples cars etc..

 

Wished..I hadn't tried it !!

And, if in a boat yard where others are painting/blacking at that time... then you are likely to be lynched!

[blackrose]

Hire the pro....its worth it! but even with all the windows, gaps etc sealed up, the grit got in, and seeing how they do it, its not an easy job! I was surprised by how powerful the stuff can be at the sort of pressure its applied... and you need to be able to get the primer on within, at the very least, four hours....

 

Why is that? If the relative humidity and dew point is such that condensation cannot form on the steel then I don't see why it couldn't be left overnight or even for a couple of days or longer if you wanted to.

Edited March 7, 2014 by blackrose

[ditchcrawler]

 

Why is that?

Which the dust or coat within 4 hrs?

[BEngo]

 

Why is that? If the relative humidity and dew point is such that condensation cannot form on the steel then I don't see why it couldn't be left overnight or even for a couple of days or longer if you wanted to.

 

 

Corrosion of the surface will occur even if there is no condensation-the absolute humidity (not relative) would have to be at desert levels for this not to happen. Some primers claim to be able to cope with a certain amount of 'gingering' as it is called, but in my experience (mainly ships) there is significant difference in the performance of coatings which are put on within 4 hours and those which are put over steel which has been exposed overnight and is gingered.

 

N

[ditchcrawler]

 

 

Corrosion of the surface will occur even if there is no condensation-the absolute humidity (not relative) would have to be at desert levels for this not to happen. Some primers claim to be able to cope with a certain amount of 'gingering' as it is called, but in my experience (mainly ships) there is significant difference in the performance of coatings which are put on within 4 hours and those which are put over steel which has been exposed overnight and is gingered.

 

N

What they use to do Offshore if the weather was out of spec was to blast all day and then the next day quickly flash over with the blast again and paint from lunchtime onwards on the fresh steel

[Ex- Member]

We coated ours within 30 minutes of the blaster leaving, fortunately it was a nice sunny day.

 

There's much mention of mess. Our shot blaster used some kind of graphite medium, just 5 meduin sized of what looked like 10 kilo bags, however we had no mess in the boat and didn't tape up the doors either.

 

The boats either side of us got covered in the debris, the shot blaster simply blew all the mess of the other boats when he finished blasting. The stuff he used wasn't like GRIT or Sand which seems to require masses of bags of the stuff, I'm told not many blasters use grit or sand any more as especially designed blast mediums work much better and more efficiently so using much less material overall.

[Timleech]

We coated ours within 30 minutes of the blaster leaving, fortunately it was a nice sunny day.

 

There's much mention of mess. Our shot blaster used some kind of graphite medium, just 5 meduin sized of what looked like 10 kilo bags, however we had no mess in the boat and didn't tape up the doors either.

 

The boats either side of us got covered in the debris, the shot blaster simply blew all the mess of the other boats when he finished blasting. The stuff he used wasn't like GRIT or Sand which seems to require masses of bags of the stuff, I'm told not many blasters use grit or sand any more as especially designed blast mediums work much better and more efficiently so using much less material overall.

 

The use of sand has been illegal for a long time, AIUI.

(Silicosis risk)

 

Tim