Sanding Anti-fouling

boatmike

boatmike

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Now I know there would appear to be an obvious "jobs-worth" H&S answer to this and that one should always wear a face mask when sanding anything, but now we have gone from TBT to Copper antifoul to be kind to the worms, just how dangerous is the dust? I have always worn a mask and usually only ever sanded wet but it would be a damn sight quicker with a power sander. Wouldn't have done it with TBT but would you/ do you with copper (with a mask of course). Anyone know the actual answer without guessing?
 
Sanding Antifouling

Most definitely still dangerous!
Antifouling consists of a paint matrix and biocides. The main biocide by volume is copper oxide but there are significant boosters that are organic biocides. Quite apart from these poisonous parts you don't want to fill your lungs with a fine powder of the paint either.
If you decide you're OK think about all the other innocent people downwind of you who will breath your dust without masks. Also the boats your blue / red / black dust will settle on.
 
Sorry but that was the obvious jobsworth answer that I could have written myself!
Can you be more definitive? What specifically are the health risks, and from what? "Organic Biocides" does not necessarily equal "Toxic to humans"
I am not asking if there is a risk, just for someone (preferably with some knowledge of the chemistry) to quantify it.... TBT was indeed seriously toxic. What I want to know on a scale of 1to10 is what are copper based ones like compared to that.
 
boatmike said:
Sorry but that was the obvious jobsworth answer that I could have written myself!
Can you be more definitive? What specifically are the health risks, and from what? "Organic Biocides" does not necessarily equal "Toxic to humans"
I am not asking if there is a risk, just for someone (preferably with some knowledge of the chemistry) to quantify it.... TBT was indeed seriously toxic.

""What I want to know on a scale of 1to10 is what are copper based ones like compared to that.""
Click to expand...

Have to say what a stupid question !!! A bit like -

"Which is safer to shoot myself in the head with a .22 or a .50 cal !"

Any dust in your lungs is bad..... you don't need a chemistry degree for that one - just "O" Level common sense !


vyv_cox - What makes you think I was concerned about his lungs ?
 
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Provided the old antifouling has been jet washed and there are no barnacles or other nasties, and provided any loose or flaking paint is removed, I never sand down the hull. However if the boat has been out of the water for several weeks I do use a large brush to remove any powder that seems to appear. This seems to be quite adequate as the new paint always stays on. I do not see the point of all that hard work if it is not necessary. I cannot recall ever seeing a large commercial vessel being sanded down either. No doubt the labour cost would be too great.
 
boatmike said:
Sorry but that was the obvious jobsworth answer that I could have written myself!
Can you be more definitive? What specifically are the health risks, and from what? "Organic Biocides" does not necessarily equal "Toxic to humans"
I am not asking if there is a risk, just for someone (preferably with some knowledge of the chemistry) to quantify it.... TBT was indeed seriously toxic. What I want to know on a scale of 1to10 is what are copper based ones like compared to that.
Click to expand...

Copper itself is pretty nasty stuff. I certainly wouldn't wish to inhale a dust containing copper oxide. And "biocide" is just a fancy word used to avoid saying "poison". Now, what is poisonous to algae and crustaceans is not necessarily so to people - but in order to work on the wide variety of fouling organisms (which span both kingdoms (animal and plant) and many families) they have to be pretty broad spectrum. I expect the precise constituents of any particular paint are commercial secrets, but I'd expect the mix to be something I wouldn't wish to inhale.

Incidentally, there is plenty of evidence that small inert particles are harmful!
 
I have sanded copper coat with a power sander, its the only way to do it. It was a quicker option, but, even with a mask, I took in aquite a bit of dust.

I would get some very coarse wet and dry paper and do it like that, I dont think anyone can really advise you that it is safe, because it wont be safe. its not just the toxic nature of the powder. the dust particles once in your lungs, I am told, will aggrevate the lung lining, throat, and air ways, cutting the lining.

I will tell you if it was dangerous in 60 years time, if I make it that far!

Is it copper paint, the more 'trendy' type?
 
akela said:
Have to say what a stupid question !!! A bit like -

"Which is safer to shoot myself in the head with a .22 or a .50 cal !"

Any dust in your lungs is bad..... you don't need a chemistry degree for that one - just "O" Level common sense !
Click to expand...

Perhaps yours was a stupid answer. It does demonstrate that you were in such a hurry to proclaim your cleverness that you didn't read the original post. There is no question of dust in the lungs, as it was stated in the OP that a dust mask was always worn. It seems like a perfectly reasonable question to me. Dust is not poisonous unless it contains poisonous substances. The question is 'Does it?'
 
Sometimes, the health and safety dragons are right.

You've asked for specific answers without providing specific facts. What brand of anti-fouling? What manufacturing batch number? How depleted? What's underneath that?

If you really want to know if dry sanding is safe, ask the manufacturer(s), but I suspect you know the answer you'll get.
 
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Judging from the effect most brands have on marine fouling, I would suggest that it is about as toxic as tap water - I should think that you could drink the stuff and it wouldn't do you any harm.

Remember when you got a splash of Kobe behind your ear, between hat and mask, and it raised a horrid painful red weal? Splash it on your skin now and you barely notice it.
 
AntarcticPilot said:
Copper itself is pretty nasty stuff. I certainly wouldn't wish to inhale a dust containing copper oxide. And "biocide" is just a fancy word used to avoid saying "poison". Now, what is poisonous to algae and crustaceans is not necessarily so to people - but in order to work on the wide variety of fouling organisms (which span both kingdoms (animal and plant) and many families) they have to be pretty broad spectrum. I expect the precise constituents of any particular paint are commercial secrets, but I'd expect the mix to be something I wouldn't wish to inhale.

Incidentally, there is plenty of evidence that small inert particles are harmful!
Click to expand...

Actually I suppose I expected that reply and certainly agree with the latter statement but still wonder what the dangerous toxins are now. I think you have a point in that we don't know what the biocides are now that we have gone back to copper but logic would suggest that as copper is less effective than TBT the additional biocides may be even more toxic to compensate. However, taken to extreme we would never use a power sander, or sandpaper by hand on anything. Wood dust is mostly toxic actually and some woods highly so but with good facemasks and extraction we use power sanders on them OK don't we? As I stated before my usual practice has always been to wet sand, if at all. Usually a scrub with a stiff brush does it. I do have quite a build up of AF now near to the WL so will be lightly sanding (probably wet by hand) to flat it down before applying another coat. I would still like to know just how toxic the material actually is now though.... Even if I do assume the worst.
 
boatmike said:
Actually I suppose I expected that reply and certainly agree with the latter statement but still wonder what the dangerous toxins are now. I think you have a point in that we don't know what the biocides are now that we have gone back to copper but logic would suggest that as copper is less effective than TBT the additional biocides may be even more toxic to compensate. However, taken to extreme we would never use a power sander, or sandpaper by hand on anything. Wood dust is mostly toxic actually and some woods highly so but with good facemasks and extraction we use power sanders on them OK don't we? As I stated before my usual practice has always been to wet sand, if at all. Usually a scrub with a stiff brush does it. I do have quite a build up of AF now near to the WL so will be lightly sanding (probably wet by hand) to flat it down before applying another coat. I would still like to know just how toxic the material actually is now though.... Even if I do assume the worst.
Click to expand...

Try http://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC33548

Just google "copper oxide toxicity"
 
Jobsworth reply for Boatmike

Never been called a jobsworth before - not even when trying to be helpful! If you don't like my answer perhaps better to just ignore rather than be insulting.

Since you give no clue as to the antifouling you used last, or maybe what you changed from in earlier years may I respectfully suggest it is a little difficult to be specific about the effects they would have if you fill your lungs with them!!!

A few simple facts. TBTO based antifoulings were a cocktail of biocides of which TBTO was just one. There were a number of other biocides included in increasing quantities as volume of TBTO reduced leading towards the ban for small boats in (IIRC) 1987.

Antifoulings today are a cocktail of biocides of which copper oxide is the most commonly used. I am not privy to the actual biocides used by all manufacturers in all their products. Certainly the main booster biocides used have changed almost completely since 1987 and the types / proportions used change on a very regular basis as legislation changes. Some of the biocides used in the early days of copper antifoulings have been shown to be far more harmful than originally thought and are now banned in the same way as TBTO. One of the main boosters available since 1987 was finally banned about 2 years ago and I'm sure that some of us will have noticed a deterioration in performance as a result.

The biocides used in antifoulings are often the same as used in weedkillers. If you would be happy to be sprayed by a farmer when crop spraying you will probably be happy breathing antifouling dust.

Personally I try to avoid breathing fine dust particles. I try very hard to avoid breathing fine particles of paint products. I try much harder to avoid breathing fine antifouling particles - not just a dustmask. If that makes me a jobsworth then please go ahead and dry sand your own antifouling - but not near me please.

As for the comment from another poster about drinking a/f because it is no more toxic than tapwater .......
 
vyv_cox said:
Perhaps yours was a stupid answer. It does demonstrate that you were in such a hurry to proclaim your cleverness that you didn't read the original post. There is no question of dust in the lungs, as it was stated in the OP that a dust mask was always worn. It seems like a perfectly reasonable question to me. Dust is not poisonous unless it contains poisonous substances. The question is 'Does it?'
Click to expand...

Well thank you for that old chap. Reading my original post again you can see that I expected the obvious and that's what I got! Also, of course someone has jumped on the bandwagon to call me "stupid" and the implication is that I am a terminal dick head with no teeth or hair! It does seem that after working for a lifetime in and around the shipbuilding industry this well may be true as I now have very little hair left although the teeth still remain intact..... We still don't have a very definitive answer though do we? The reason I asked in the first place is that while I do have a very sophisticated full head rear feed "space helmet" which is left over from the days of inspecting the inside of tanks on ships, I really feel that with good ventilation in the open and a good "front filter" face mask using a power sander with an industrial vacuum cleaner I would not be at (or cause others) a risk. It's impossible of course to get any real info on the toxicity of "modern" anti-foul so I guess when in doubt treat as worst case. I had hoped someone would know a little more in terms of detail though....
 
Well before the discussion gets so heated it is banned like discussing climate change in the lounge, there are better ways of sanding anyway.

Firstly why sand at all? Well you can just pressure wash and recoat most antifouls but any flaky bits will still fall off and take expensive new paint with it. The surface will get rougher and thickness even with the wear away modern stuff will still build up. Rough is SLOW!

Wet sanding by hand is er.. wet and slow. Until that is I was introduced to the bit of kit that builders and plasterers use to sand walls and ceilings. This is a universally jointed holder that holds a special sanding sheet in the same way and size with clamps as on an orbital sander, this head fits onto either a short or a long pole. The sanding material is the real little helper as it is an open mesh material that doesn't clog and lasts and lasts. You need to wet the hull first ahead of where you are working, then use this sander wet to get a real sludge going and work your way round the hull, hosing off say every 4ft or so and wetting the next bit along. The difference is the pole and holder keeps you (and your arms and sleeves) out of the water, you get real pressure on where you are sanding, the paper doesn't tear and fall apart and it doesn't keep clogging up, just hose it off as you move along to the next section.

Using the device above, I have sanded the entire hull of a deep keel 41 footer in an afternoon on my own and in even less time with help from SWMBO wielding the hose. The finish is so much better, less paint build up and better adhesion.

These wonder gizmos are available from decorators supply shops, mine came from Brewers in Poole. The heads and poles cost around £10 and about the same for a sizeable length of the sanding mesh stuff sold by the metre, I bought enough for £10 to last several years. I used one cut sheet for each side of the hull.
 
akela said:
Try http://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC33548

Just google "copper oxide toxicity"
Click to expand...

Well thank you! I did that and also compared the results with other common chemicals like TDI. Very interesting actually because I can't find anything that says the material is any more than "moderate" in the scale of toxicity and the risks seem to be only associated with very high ingestion rates. Also found http://ec.europa.eu/health/ph_risk/committees/04_scher/docs/scher_o_100.pdf which says that the danger of copper deficiency in the body is actually a greater risk than it's toxicity in larger doses! The actual quote is as follows

"The concentration of copper in the body is strictly and efficiently regulated by
homeostatic mechanisms. Systemic effects ensue but the capacity of the homeostasis is
exceeded. The major control mechanism is gastrointestinal absorption and biliary
excretion into faeces. Liver has an important role in the maintenance of the copper
homeostasis. The failure to maintain homeostasis may lead to adverse effects resulting
either from deficiency or excess.
Copper deficiency causes more and far severe adverse health effects than copper
toxicity."

I went further and asked my doctor friend if this was true and she confirmed it!
So the idea that copper itself is by nature "very nasty stuff" as another poster put it is total rubbish and yet another example of the fact that people post what they believe is an obvious answer without researching it or having any detailed knowledge themselves. Often the obvious is not so! The question still remains however regarding other biocides that may be present, and I take the point made by others that this may well vary with the manufacturer and brand.
 
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Robin, I think you have described this gizmo before but I've not been able to find it in catalogues such as Screwfix - is there a trade name for this item so that I can do a specific search?

No need to respond - some more serching found the item - a swivel pole sander head
 
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