27 replies to this topic

[ChopperHarris]

Etch primer is completely unnecessary on either fibreglass or steel if properly prepared, ie there is a suitably keyed substrate. Save your money

[neal]

I prefer 2K etch primer, then a coat of high build 2K which is the most common type of primer nowadays, it's best practice not to mix and match different components (1k & 2k) to avoid pickling (paint component reaction) whereby you will have to strip it all back to metal again.

 

It is possible to use UPOL No.8 aerosol (red can) but a really light coat and you takes your chance.

[pete l]

This is worrying, I'm using 1K primer for the repair work on my MPI and planned on using 2K once everything is finished, does this mean I have to go back to bare metal ?

[tiger99]

Not necessarily.

Do you have all the correct protection for using 2k, including full impervious suit and air fed mask, as well as venting the fumes safely? If not, don't kill yourself, don't use 2k.

[pete l]

Errr, No I don't, how can I get a good finish with 1K ?

[Daz1968]

Best 1k I have used was upol smartclear rfu clear coat. You could use this over solvent basecoat,
If you want to use 2k you need an airfed mask, usually another compressor as well to keep up with it.

[Dusky]

2k etch Just means you Have an etch where youadd the acid yourself. 1k Will Be good if it wasnt past its use by date

[Dusky]

2k etch Just means you Have an etch where youadd the acid yourself. 1k Will Be good if it wasnt past its use by date

[tiger99]

Yes, but there was mention of 2k high build, and if you inhale more than a very tiny amount of that you die or live a totally miserable life thereafter. It is highly toxic, hence the need for precautions. And, I don't know how you protect the neighbours from what will leak out of your spraying area. I am well experienced in doing potentially unsafe things, with the right precautions, and trained in handling chemicals, but that stuff frankly scares me because so much can go wrong.

Just suppose the electricity supply fails. Compressor stops so no air feed to mask. Lights go out. Will you make it safely to clean air outside? Not saying you can't, but it is the sort of thing that has to be provided for.

I may need to spray the stuff myself one day so it is of interest. And so especially are primers. But it is not the part of Mini restoration that I look forward to with pleasure. Give me a brake clevis pin any time. At least they don't poison you.

[pete l]

If this 2K stuff is really that dangerous, then why is it readily available to buy ? I've used it before, outside without any kind of protection, this was before I knew about all the dangers. The shop that sold it to me never mentioned it either.
I used a small can of 2K clear coat the other week with no protection, I had to break a seal to mix the 2 parts together.
Am I going to die now ?????

[Shifty]

If this 2K stuff is really that dangerous, then why is it readily available to buy ? I've used it before, outside without any kind of protection, this was before I knew about all the dangers. The shop that sold it to me never mentioned it either.
I used a small can of 2K clear coat the other week with no protection, I had to break a seal to mix the 2 parts together.
Am I going to die now ?????

To be honest you could, it really depends on the person.  Some people have a high tolerance and other can get seriously ill from just using it once.

 

There is no hard and fast rule on the exposure risk, every time you use it without protection(and more importantly the correct protection) you are playing Russian roulette with a variety of potential risks.

 

It is freely available but it is very much buyer beware.

[neal]

This is worrying, I'm using 1K primer for the repair work on my MPI and planned on using 2K once everything is finished, does this mean I have to go back to bare metal ?

Like I mentioned earlier, You can use a 1k acid etch primer such as UPOL no. 8 on you scuffed bare metal making sure that you use a panel wipe degreaser before application, but only a light coat is all you need.

 

You can put 2k high build primer on top but make sure that you don't wallop in on because it will take time for the curing process. Remember, your 2k high build primer depending on the manufacturer will state a ratio of primer to hardener (either 2 parts primer:1 part hardener or 3:1 ratio) also the manufacturer will advise you on how much 2K thinner to add to the mix for the flow out of the gun and onto the panel.

 

I personally use UPOL 20:20 HS (high speed) Primer Filler (3:1 ratio), it has a 6hr cure time at 20 degrees C and a 30 min cure time at 60 degrees C. I use and add 10% high speed 2K thinners to my mix.

UPOL recommends (All information taken from the tin) 280 - 360 grit production paper to block it.

Wet sanding 320-400, 600-800

 

Now, this particular stuff can be used in a wide temp band ( not necessarily used in a heated spray booth at 60 degrees, but in theory in a warm climate as per info on tin), but....If you use this in colder climates it will take longer to cure whereby it COULD soften the 1K acid etch primer underneath losing it's grip, hence my term 'and you takes your chance'

 

This stuff is for professional use (it contains isocyanates, google it) and must be treated accordingly with respect, If you choose to use this I would suggest you as mentioned by others use an air fed mask and a big compressor with filters. I would not recommend using this in your garage as there will be not enough extraction and your neighbours will be attracted to a strong smell of pear drops. If it does get out of your garage, pray that the overspray doesn't stick to your neighbours car! 

 

If you do breathe this stuff in and depending on how much for how long ( also depending on your tolerance) you will suffer from dizziness, nausea, possible blurred vision and in serious over exposure, a tightness of the chest that will scare the crap out of you! A friend of mine went to the hospital, had an x-ray and a shadow was noted on his lungs. (He is a painter by trade and took it for granted for too long, took a silly risk too many times)

 

However,I have known some people to use this stuff out of a booth but in a large farm barn with doors wide open on a warm day, no neighbours to complain and an air fed mask, had good results and had no ill effects.

 

As I said 'You takes your chance' 

 

One last thing...... If you do use this stuff I.E. high build 2k primer at the lower temp range, leave the panels for a good two/three days to really harden properly before blocking/wet sanding as it is still very slightly soft, not to the touch but the paint will sink and settle. Don't rush a good thing! 

Edited by neal, 19 October 2016 - 12:04 AM.

[pete l]

Thanks for that neal.

 

I think I will stick to epoxy primer, water based colour and then decide on what type of clear coat, probably 1K.