Utter Noob Guide to Spray Gun Installation

Utter Noob Guide to Spray Gun Installation

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CamMoreRon

Original Poster:

1,237 posts

124 months

Wednesday 27th August 2014
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Morning chaps..

I'm after a bit of professional / advanced advice on sorting out a spraying installation in my workshop. I've had a bit of a dig round on the internet and found most of the basics of system layout, but I don't really know where to start when it comes to brands or sourcing the equipment.

The first job is to spray my race car with primer, base and clear, but I will no doubt have more jobs for it in the future! I am very much of the mantra "buy right, buy once" and prefer to pay for quality over buying crap that breaks / wears out / doesn't work properly.

The main things I need help with are:

Choosing the right spray gun - I've heard of DeVilbiss, Iwata and SATA, and my budget is around the £300 mark. I want to use HVLP equipment but I have no idea about nozzle sizes or any of the details!

Installing the air feed - I have a 14cfm compressor with 150l tank, but need to get the solid pipes, connectors and flexi hoses in. Does anyone know a good source?

Filter / regulator - Can anyone recommend a good water filter and regulator for spraying? As above I would prefer to use HVLP equipment. Also need a good source!

Finally.. Paint! - Where is a good source to get decent quality paints? What are the laws on what I can and can't paint with in my workshop?

There's probably a bunch of stuff I have overlooked, so if you have experience with setting up a high quality spraying installation please feel free to add anything you think might be necessary. smile

7even

462 posts

192 months

Wednesday 27th August 2014
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Spray guns direct will be able to supply the "lot" although you may need to upgrade your compressor to run a full size gun and mask adequately.
Along with the above, smart express or express paints will also through a system together for you.

Also if your a member of any of the established paint forums you'll receive a discount from the above mentioned firms for equipment and consumables.

CamMoreRon

Original Poster:

1,237 posts

124 months

Wednesday 27th August 2014
quotequote all
Thanks for the reply. I think the compressor I have will be ok for the size of job I have at the moment, but if I'm wrong then I can upgrade that later.

I'll have a look on some painting forums for now.

Squiggs

1,520 posts

154 months

Wednesday 27th August 2014
quotequote all
CamMoreRon said:
Thanks for the reply. I think the compressor I have will be ok for the size of job I have at the moment, but if I'm wrong then I can upgrade that later.

I'll have a look on some painting forums for now.
?????? To supply an air fed whilst doing a respray will push a 150ltr

CamMoreRon

Original Poster:

1,237 posts

124 months

Thursday 28th August 2014
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Squiggs said:
?????? To supply an air fed whilst doing a respray will push a 150ltr
As I understand it, tank size doesn't really matter.. it's the output of your pump that's important.

As the job size is pretty small I think my compressor will be ok. Worst case is I have to wait for it to recover occasionally.

leather

2 posts

207 months

Friday 29th August 2014
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Hi, if your not painting alot & have suitable extraction go with a quality charcoal filtered mask as you will need all your 14cfm for the gun.
All your fittings & airline need to be hvlp & any of the guns you mentioned will do a grand job, however there are base guns & clear guns & if you only want one I would go with a base gun for the finer atomisation & work a little harder laying the clear down.
For the filter regulator, if your not running air fed mask you only need a two stage jobie, again devilbiss or sata are top notch.
Hope this helps, I have 30 years exp painting.

Steve

CamMoreRon

Original Poster:

1,237 posts

124 months

Monday 1st September 2014
quotequote all
Cheers Steve.

It's just the one car at the moment, and it'll be painted in front & rear clam halves, doors, and frame, so I can break the spraying up in to small chunks. Later on I would like to spray whole cars, but I don't have the space right now. I'm in a small workshop and will just create a temporary dust-free area to paint in, so extraction isn't going to be great.

It's a bit of money to get an air-fed mask, but it beats becoming a respiratory cripple so I don't mind!

Byteme

450 posts

141 months

Wednesday 10th September 2014
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CamMoreRon said:
Cheers Steve.

It's just the one car at the moment, and it'll be painted in front & rear clam halves, doors, and frame, so I can break the spraying up in to small chunks. Later on I would like to spray whole cars, but I don't have the space right now. I'm in a small workshop and will just create a temporary dust-free area to paint in, so extraction isn't going to be great.

It's a bit of money to get an air-fed mask, but it beats becoming a respiratory cripple so I don't mind!
If you only have a small workshop where do you propose siting the compressor and how do you intend extracting and safely venting you painting area? Air fed equipment could be the worst method of protecting yourself unless the two areas are kept isolated from each other.

Don't underestimate the amount of over-spray and solvent fumes that will accumulate in a poorly ventilated area.

CamMoreRon

Original Poster:

1,237 posts

124 months

Friday 12th September 2014
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Byteme said:
If you only have a small workshop where do you propose siting the compressor and how do you intend extracting and safely venting you painting area? Air fed equipment could be the worst method of protecting yourself unless the two areas are kept isolated from each other.

Don't underestimate the amount of over-spray and solvent fumes that will accumulate in a poorly ventilated area.
The compressor is in my workshop, but I'm looking in to extending the inlet so it draws fresh air from outside if I were to use an air-fed mask.

The "booth" will just be a sealed area of the workshop, with some sort of extraction to get the worst of the mist out.

What would you recommend if I couldn't get adequate fume extraction to use an air-fed?

Byteme

450 posts

141 months

Tuesday 16th September 2014
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CamMoreRon said:
The compressor is in my workshop, but I'm looking in to extending the inlet so it draws fresh air from outside if I were to use an air-fed mask.

The "booth" will just be a sealed area of the workshop, with some sort of extraction to get the worst of the mist out.

What would you recommend if I couldn't get adequate fume extraction to use an air-fed?
How much painting do you intend to carry out and using what materials?

You really need to get the compressor out of the workshop well away from any area you intend to use for spraying.

Extraction tends not to work as easily as you may imagine as it will take away fumes and over-spray but it will also draw in dirt. A proper booth maintains a positive pressure using a series of baffles but you could approximate this by using a larger fan to blow filtered air in while using a smaller one to extract. Whatever you choose the fan motors will need to be flame-proof.

If you intend spraying an entire car with a decent gun you'll need a big compressor and 3hp is about as much as you can use from a 240v supply. That won't leave enough of a reserve for an air fed mask. Air-fed masks also require additional filtration.

CamMoreRon

Original Poster:

1,237 posts

124 months

Sunday 21st September 2014
quotequote all
Byteme said:
How much painting do you intend to carry out and using what materials?

You really need to get the compressor out of the workshop well away from any area you intend to use for spraying.

Extraction tends not to work as easily as you may imagine as it will take away fumes and over-spray but it will also draw in dirt. A proper booth maintains a positive pressure using a series of baffles but you could approximate this by using a larger fan to blow filtered air in while using a smaller one to extract. Whatever you choose the fan motors will need to be flame-proof.

If you intend spraying an entire car with a decent gun you'll need a big compressor and 3hp is about as much as you can use from a 240v supply. That won't leave enough of a reserve for an air fed mask. Air-fed masks also require additional filtration.
Good info, thanks. smile

I hadn't thought about the negative pressure sucking dust in.. that would be a big problem as my workshop is very dusty! I'm not going for a show car finish by any means, but I do want it to be as good as it possibly can be for my level of experience. (Zero)

I might have to think about a small 240V compressor for supplying the mask in that case. I think if I put one of those outside the unit and used a 20m hose to route it to my mask, that might be a good solution.

It's fixable...

468 posts

204 months

Thursday 2nd October 2014
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Not wishing to sound like an arse but the post about maintaining positive pressure in the spray booth cabin is totally wrong and illegal.

Negative pressure between 0 and -20pasacals must be maintained in the spray booth cabin to avoid ejecting nasties out into the workshop.

Take some time to familiarise yourself with the various health and safety publications and the requirements given therein - there are stacks! Also make sure you are familiar with the requirements of ATEX and have a good grasp of the concept of zoned areas.

Then and only then attempt this project.

Oh, and before the flaming starts, this is what I do for my day job...


CamMoreRon

Original Poster:

1,237 posts

124 months

Friday 17th October 2014
quotequote all
It's fixable... said:
Not wishing to sound like an arse but the post about maintaining positive pressure in the spray booth cabin is totally wrong and illegal.

Negative pressure between 0 and -20pasacals must be maintained in the spray booth cabin to avoid ejecting nasties out into the workshop.

Take some time to familiarise yourself with the various health and safety publications and the requirements given therein - there are stacks! Also make sure you are familiar with the requirements of ATEX and have a good grasp of the concept of zoned areas.

Then and only then attempt this project.

Oh, and before the flaming starts, this is what I do for my day job...
Thanks for the input. smile

Could you give me some advice on filtering the extracted air? I want to duct it from the extraction fan out the workshop, but I want to make sure I filter it properly as it's a semi-residential area and I don't want to pump isocyanates out everywhere.

I've seen the panel type filters you can get for extraction, but are these enough? They don't look like much to my untrained eye, but they claim to filter out ~99% of particulate. Is it enough to have one of these in front of the extractor vent, or do I need more?

I think I'm getting there with the concept now.. air lines and everything should be done in a couple of weeks, then I'll get round to making the booth. I will DEFINITELY use an air-fed mask, and make sure my inlet & outlet filtration is adequate. I want to do this properly. smile

It's fixable...

468 posts

204 months

Friday 17th October 2014
quotequote all
First things first.

What is the height x width x depth of your spray area; assuming the width dimension is the same side you'll have your extract filters on. You need to maintain an average of 0.7m/second airflow across the height x width cross sectional area. This will give you an airflow size for the extract fan.

Now you are pulling air out! But how will you get an equal amount of replacement air in? Ideally it will come down through the "roof" and will be filtered so it is clean and doesn't leave a load of contaminants in your spray job.

Post some photos or sketches of your spray area and the surrounding structure.

Also be aware that to be legal your spraying area will need planning permission and approval by the local environmental and petroleum officers. If you have anyone in there spraying for you, you will need a LEV test certificate...

Plus the exhaust stack must be 3m higher than the roof peak - a red rag for any nosey parkers in the neighbourhood...

CamMoreRon

Original Poster:

1,237 posts

124 months

Friday 17th October 2014
quotequote all
It's fixable... said:
First things first.

What is the height x width x depth of your spray area; assuming the width dimension is the same side you'll have your extract filters on. You need to maintain an average of 0.7m/second airflow across the height x width cross sectional area. This will give you an airflow size for the extract fan.

Now you are pulling air out! But how will you get an equal amount of replacement air in? Ideally it will come down through the "roof" and will be filtered so it is clean and doesn't leave a load of contaminants in your spray job.

Post some photos or sketches of your spray area and the surrounding structure.

Also be aware that to be legal your spraying area will need planning permission and approval by the local environmental and petroleum officers. If you have anyone in there spraying for you, you will need a LEV test certificate...

Plus the exhaust stack must be 3m higher than the roof peak - a red rag for any nosey parkers in the neighbourhood...
Dimensions are roughly H 5.0m, W 3.5m, H2.5m

It'll be a sealed area in my workshop.. only temporary, mind, as I will only be doing the one spray job. I don't think it will be possible to have air drawn in through the top of the booth as the roof is pretty dodgy and leaks in places.. I was planning to have an inlet with some panel filters at one end and the exhaust(s) at the other, then duct out the roof fascia at the front of the workshop.

The workshop is rented on private land which the landlord lives on. He knows about my plans to spray in there and is happy for me to just spray to atmosphere, but I'm not happy to do this. I think planning permission will be going a bit too far for the scope of my work.. probably not what you would like to hear. laugh

As for nosey parkers there is no risk of that.. the unit is right at the back of this guy's land and really out in the sticks.

I just want to make sure I'm not going to take any undue risks to my own health (or my landlord's) and the environment.

Squiggs

1,520 posts

154 months

Saturday 18th October 2014
quotequote all
CamMoreRon said:
I just want to make sure I'm not going to take any undue risks to my own health (or my landlord's) and the environment.
Which you can't do unless you (inform the local authorities and) abide to all the HSE regulations .....!?


It's fixable...

468 posts

204 months

Saturday 18th October 2014
quotequote all
If the cross section of the cabin is 5m wide x 2.5m high then to keep it safe (and legal) you will need an extract fan with an airflow rate of 31,500m3/hour.

If the cross section of the cabin is 3.5m wide x 2.5m high then to keep it safe (and legal) you will need an extract fan with an airflow rate of 22,050m3/hour.

I do not think you will be able to safely lash up something temporary unless you hire a lot of ATEX rated air mover fans...

CamMoreRon

Original Poster:

1,237 posts

124 months

Saturday 18th October 2014
quotequote all
It's the 2nd one.

Hmm.. that would be 7 300mm ATEX fans from what I can find on the internet, at a cost of £800 per week. Not going to happen! laugh

I understand you're giving me advice from experience with a permanent spray booth, to be as safe as possible, and compliant, but that is too expensive! I could afford one, realistically, two at a push.

What filter elements should be used ahead of the extraction?

benters

1,459 posts

133 months

Tuesday 28th October 2014
quotequote all
following this thread with interest, and can see lots of super useful advice. To get round the issue OP is it possible to rent a proper setup from a pro body shop these days ? get the Pug done and then tackle the complex issues over the legals and stuff another time. I suggest this only as I will at some point be in the same position as you and its the route I may choose.

Squiggs

1,520 posts

154 months

Tuesday 28th October 2014
quotequote all
One thing I haven't seen mentioned (unless I've missed it) is that the fumes can be flammable and any motors for fans etc should therefore be approved.