2K Safety - Leason learnt

[Jbo2231]

I wouldn't expect anyone coming from a professional background directly related to the regulations would be willing to say you dont need one, but please prove me wrong If I am as it will make my build a lot cheaper!

Most paint fumes can be made in to an explosive in the right concentrations and environment. If you were building a spray booth in a bodyshop you would need explosion proof fans.

I think you have done the right thing in buying explosion proof (just make sure it comes with the correct certification that looks genuine). And i would thank you if you were my neighbour or i was your house insurer for doing the responsible thing.

Yes, you may well get away without one just for occasional use but is it really worth the risk of blowing yourself up for the sake of a few hundred pound? Even If it wasnt a major accident the loss of earnings from cost and time spent performing repairs to the building or time off work, or the council on your back would quickly make a few hundred look like peanuts.

Just make sure you use the correct PPE and pay attention to the other electrical items in the booth. It's easy to forget about lighting, or grounding anything that could cause sparks (pvc ducting, pvc wall panels, metal ducting) and make sure you seal everything nice and airtight. Aluminium tape works well for making an air tight seal on a budget.

I'm not a professional or expert by any means and may be going overboard with the grounding and things but better to be safe than sorry! It isnt cheap to do properly but if you do a couple of full resprays you should break about even.

 

[Little Jerry]

Thanks mate, I agree with the points you made- trying my best to do it properly. I'm about $2000 AUD in with this build so thinking I am doing it as professionally as I can within reason. Sealed LED's, sealed extraction fan, proper paint booth filters and carbon filters, dedicated room, breathable air supply unit. I want to learn it all myself, but that aside, I figure to professionally get the body work and paint (inside out) would cost me $15K -$25K AUD approximately, so $5K (air compressors / spray guns / booth etc) is worth it if i can get a 8.5-9/10 job which i think is doable.

 

[Little Jerry]

I know I have touched on this before, but can anyone provide any clarity / opinions:

With regards to 2K paint spraying - I was told by a person who sells spray booth filters for a living that if I have proper spray booth filters that their understanding was that the amount of isocyanate potentially vented to the atmosphere would be so diluted that it is no worse than say air pollution from a car.

Is this a fair statement?

Most of the information I can find relates to the safety of the person in the booth spraying as opposed to safety precautions for venting to atmosphere.

 

[Jbo2231]

The exhaust fumes from a car and from a spray booth are not comparable. The chemical make up is completely different.
This is the reason why I decided against a DIY booth. I was happy with my safety and PPE but my neighbours gardens are 5m from where the exhaust filters would be located. There is also corn being grown in a field 15m from where the exhaust would be.
I personally thought that if I was exposing them to any Isos at all that was unacceptable.
People have a right to clean air, especially around their homes. Its why in the UK you dont have body shops and mechanics shops in residential areas.
However it depends on your location. If I lived in Wales on a farm I wouldn't hesitate to build a booth as long as it was a fair distance from my crops or anybody elses.
You need to consider food safety, public footpaths, farmers wellbeing etc etc etc.
Good to see that you are considering the environmental impact you may he having so thank you for that!

 

[Little Jerry]

Appreciate the feedback mate....I think we are alike in how we have approached this - at the end of the day it's just a paint job.

I just need some real world testing - I can get 2K epoxy that is isocyanate free to get me started, so once my booth is completed I think I will use that product to test how the filtration system performs. I will be doing bodywork for at least a year, so just need the epoxy at first, so I can make improvements to the booth extraction down the track or stick with the iso free products. Already have concertina filters followed by active carbon filter so will see what gets through that combo.

Would a VOC meter be of use in this situation assuming that if VOC's in the solvent are present in the air then so are the isocyanates? Would be nice to measure things but I think it's getting into specialised expensive equipment.

The andreae concertina filters data sheet have 90+% efficiency (98% for high solids) - am I correct in interpreting that to mean it captures 90+% of the overspray?

 

[Little Jerry]

Apologies if this is an ignorant question - do activated carbon filters trap / absorb isocyanate vapours or just remove the odor from paint solvents etc?

Trying to determine whether a combination of overspray mist filters coupled with activated carbon filters for vapour filtration would mean the exhausted air from a spray booth would be relatively clean?

I see activated carbon filters used by people with respiratory half masks so I'm thinking it would have to be somewhat effective at absorbing the iso's - if only for a certain period?

 

[Jbo2231]

This article MAY be helpful for you. I have only skim read it and you need to understand it's about how effective mask filters are. However it discusses activated carbon filters role in filtering isocyanates.

https://academic.oup.com/annweh/article/54/4/377/273604

Here is a quote of the conclusion:
The thermal degradation of urea and dimethyl urea enabled the continuous generation of stable air concentrations of ICA and MIC. PTR-MS enabled direct and continuous monitoring of isocyanates.

In the breakthrough tests, both the SR 515 and the SR 599 filters protected efficiently against ICA and MIC, and no trend of impaired performance was observed throughout the 48-h exposure tests, not even for filters pre-exposed (48 h) to high concentrations (100–200 p.p.b.) of ICA and MIC.

The hydrolysis of activated carbon from exposed filters can be used to reveal the penetration of isocyanates in the filters. With time, the penetration reached further down in the filters. There is a strong indication that the filters efficiently absorb HDI and IPDI for concentrations relevant for working life.

END QUOTE --

It should go without saying now but ALWAYS use an air fed mask when spraying.
I would also suggest changing the carbon filters with every project, its overkill but they have a relatively short life span and if you're forcing unknown quantities of air through them you dont know how long they will last.
I would also look in to getting a urine test for isocyanates to monitor your exposure to make sure nothing has slipped through your ppe net.
Again, overkill.. but you only get two lungs and you have such an amazing country to explore you dont want to be buggering them up!

 

[Little Jerry]

Yeah I should have mentioned that I have a supplied air system...I was just thinking that the activated carbon in the exhaust filtering setup would absorb some of the voc's much like it does with the half mask respirators.

Iso paint or not, at a minimum seems like a good way to minimise smells etc

 

[Jbo2231]

Yeah I should have mentioned that I have a supplied air system...I was just thinking that the activated carbon in the exhaust filtering setup would absorb some of the voc's much like it does with the half mask respirators.

Iso paint or not, at a minimum seems like a good way to minimise smells etc

Yeah I would think it would work to a degree but I'm not sure how much, may be 99% removal? May be 10% removal. I imagine it varies depending on how well sealed the room is, the rate of air flow, if the air is being sucked through the filter or pushed through it etc etc. Would probably be best to ask the manufacturer what their filter is capable of removing and the requirements of installing it.

As a side note one of the many articles I read mentioned that it takes far longer for the room to completely clear compared to what you can actually see. Basically you can only see a small amount of the fumes/spray, cant remember the percentage.
I'm sure you're aware that isocyanates dont have a smell but I guess you mean it will just help with the smell in general.
Sorry I cant give you a more detailed answer as to how effective the carbon filters will be. Hopefully someone with some more knowledge will come along and I hope you can get a system going that works for you.

I only mention this because it's the route I have chosen. Have you looked at renting a booth when you need it? I can rent a professional booth for a 10 hour day around 15 times for the cost of making a DIY "safe" booth. So can probably paint around 7 cars if I do most of the bodywork at home first and just spend a day doing final primer and prep.

 

[Parm]

do activated carbon filters trap / absorb isocyanate vapours

somewhere in this thread I’m sure I’ve provided all the answers to your questions

 

[Jbo2231]

Not sure if I have confused people by linking an article relating to masks. Sorry if I have! It
was just to show that activated carbon is used in filters that are sold to protect against isocyanates. It was a poorly chosen article considering the previous debates on the subject, Little Jerry was looking for information as to if a filter on a booth would remove the isocyanates for the protection of anyone breathing the air outside the booth.
I read through this thread a while ago but unfortunately it got a bit hard to read, I may have missed Parm covering booth filtration, I would take his advice on the subject over mine any day of the week.

 

[Little Jerry]

Appreciate the info guys...just good to bounce ideas off, not expecting you to have all the answers.

I just realised that years ago I used a product years ago called KBS Rust Seal which was a moisture cured urethane to rust proof my truck chassis. It was advertised as brush on etc, but you could spray it for best results. I had purchased my supplied air respirator, but I was unaware it contained isocyanates and just assumed it was like any other paint you buy over the counter. I sprayed that in my shed with a bathroom fan, flourescent lights, and no exhaust filters.

 

[Little Jerry]

Apologies for all the questions - just thinking if I bought a non industrial VOC meter that recorded data and put it at my exhaust location that would give me an idea on the effectiveness of my filtration system? Or is their a spectrum of VOC's that need more expensive specific equipment? Not sure if anyone has any idea with this.

 

[Little Jerry]

somewhere in this thread I’m sure I’ve provided all the answers to your questions

I went and re-read the entire thread and I didn't see any comments relating to this...given it's your profession I'd be interested in your take on the effectiveness of activated carbon - I would assume the volume ratio of activated carbon vs vapours would play a big part in its effectiveness.

 

[Parm]

I went and re-read the entire thread and I didn't see any comments relating to this...given it's your profession I'd be interested in your take on the effectiveness of activated carbon - I would assume the volume ratio of activated carbon vs vapours would play a big part in its effectiveness.

any type of filtering RPE is not recommended for isocyanates

isocyanates have no taste or odour. If your spraying and create a mist then it has to be air fed RPE

I’m sure I’ve posted this guidance before

General Guidance
https://www.hse.gov.uk/mvr/bodyshop/isocyanates.htm

Spray Booths
https://www.hse.gov.uk/pUbns/priced/hsg276.pdf

 

[Little Jerry]

Any experience with the effectiveness of activated carbon as part of the exhaust filtration?

The document mentions 2 stage exhaust filtration - is that for mist and vapour?

 

[Parm]

Any experience with the effectiveness of activated carbon as part of the exhaust filtration?

The document mentions 2 stage exhaust filtration - is that for mist and vapour?

I can’t help with exhaust filtration discharge / abatement as it’s not something I know about

What I do know is that the pro shops have to have the necessary discharge permits. One of the conditions is the mass of solvents they can emit and dispersion of solvent vapour in the air.

dispersion is worked out using a D1 stack height calculation, computer modelling and topography data of nearest senestive receptors. It’s way beyond what I know

 

[Jbo2231]

I can’t help with exhaust filtration discharge / abatement as it’s not something I know about

What I do know is that the pro shops have to have the necessary discharge permits. One of the conditions is the mass of solvents they can emit and dispersion of solvent vapour in the air.

dispersion is worked out using a D1 stack height calculation, computer modelling and topography data of nearest senestive receptors. It’s way beyond what I know

Hence why they are built in industrial areas and not residential..
Little jerry: I imagine you have reached the limit on the advice you can get for this on the internet and you would need to consult a professional from your country for further guidance.
I understand and appreciate that you are trying to do the best you can at home to keep everyone safe. I have done a couple of months of casual reading regarding the guidance in the UK and have come to the conclusion that it is not safe or appropriate to spray 2k at home unless you live in the **** end of nowhere and far away from anyone or anything else. Even then you should follow the advice Parm has given in the past.
Best of luck with whatever you decide, I dont think I have anything else worthwhile to contribute, sorry!

 

[Parm]

Hence why they are built in industrial areas and not residential..
Little jerry: I imagine you have reached the limit on the advice you can get for this on the internet and you would need to consult a professional from your country for further guidance.
I understand and appreciate that you are trying to do the best you can at home to keep everyone safe. I have done a couple of months of casual reading regarding the guidance in the UK and have come to the conclusion that it is not safe or appropriate to spray 2k at home unless you live in the **** end of nowhere and far away from anyone or anything else. Even then you should follow the advice Parm has given in the past.
Best of luck with whatever you decide, I dont think I have anything else worthwhile to contribute, sorry!

The firm I worked at for 25 years did all this sort of thing. It involved lots of computers and maths, I’m rubbish with both, lol

 

[Little Jerry]

No dramas, well i appreciate all the help as I was able to get some good information from this forum.