Tips for first time using 2k Epoxy Primer

Robotsan

Club Member
Hi all,

I'm planning to primer the floors of the 280z this coming weekend, using Lechler 2k 29107 (as recommended by @jonbills and @candy red ) in light grey. Having never used primer or painted a car floor before, I just want to make sure I get it right.. if possible!

I'll be painting it on so as not to die from isocyanate inhalation - which I think is the main thing to get right. But I'm also wondering about the following..

1. I was thinking of just primering the floors up to where the remaining factory sound deadening is (see below) - or should I go over the old stuff on the trans tunnel too? It would need cleaning up obviously. The downside is then its more that I'll have to paint with the factory 307 Silver Metallic paint. Alternatively, as this will all be covered up anyway, I could just give it a clean and leave it.

1664196375290.png


2. Will brushing the top coat (307 silver) over the primer be ok? As ideally I don't want to spray anything as it means spending a lot more on new equipment for something I'll do extremely rarely/never again, and it'd be tricky not getting any drift or overspray on things.

3. When mixed, how long can the primer stay in the mixed state? I've found this technical data sheet from Lechler which says the 'pot life' (which I assume is what I'm talking about) is 4 hours with standard hardener..

1664197602846.png

...but I'm using the speedy hardener (29371).. it just says it causes "a reduction", but not by how much!:

1664197853926.png

4. Will 1 litre of primer be enough for both floors? It says this in the tech sheet..

1664197548788.png

.. but this is in the section about spraying. Would it be the same when brushing it on?

5. Can I just use normal paint brushes?

6. Can I use normal masking tape / frog tape to get a nice clean edge around it?

7. Any other tips?!

Many thanks in advance.
 

jonbills

Membership Secretary
Site Administrator
Hi all,

I'm planning to primer the floors of the 280z this coming weekend, using Lechler 2k 29107 (as recommended by @jonbills and @candy red ) in light grey. Having never used primer or painted a car floor before, I just want to make sure I get it right.. if possible!

I'll be painting it on so as not to die from isocyanate inhalation - which I think is the main thing to get right. But I'm also wondering about the following..

1. I was thinking of just primering the floors up to where the remaining factory sound deadening is (see below) - or should I go over the old stuff on the trans tunnel too? It would need cleaning up obviously. The downside is then its more that I'll have to paint with the factory 307 Silver Metallic paint. Alternatively, as this will all be covered up anyway, I could just give it a clean and leave it.

View attachment 53742


2. Will brushing the top coat (307 silver) over the primer be ok? As ideally I don't want to spray anything as it means spending a lot more on new equipment for something I'll do extremely rarely/never again, and it'd be tricky not getting any drift or overspray on things.

3. When mixed, how long can the primer stay in the mixed state? I've found this technical data sheet from Lechler which says the 'pot life' (which I assume is what I'm talking about) is 4 hours with standard hardener..

View attachment 53744

...but I'm using the speedy hardener (29371).. it just says it causes "a reduction", but not by how much!:

View attachment 53745

4. Will 1 litre of primer be enough for both floors? It says this in the tech sheet..

View attachment 53743

.. but this is in the section about spraying. Would it be the same when brushing it on?

5. Can I just use normal paint brushes?

6. Can I use normal masking tape / frog tape to get a nice clean edge around it?

7. Any other tips?!

Many thanks in advance.
IMO:
1) Either will fine, but primering it seems unnecessary work to me.
2) yes, it'll just look brushed.
3) I don't know. I'd guess it'll still be plenty of time.
4) yes plenty, I reckon I put about 1/4 litre on each floor.
5) I used cheap disposable paint brushes.
6) yes. I think you probably need to remove the tape before it hardens, just in case it takes the paint with it.
7) nope.
 

Robotsan

Club Member
IMO:
1) Either will fine, but primering it seems unnecessary work to me.
2) yes, it'll just look brushed.
3) I don't know. I'd guess it'll still be plenty of time.
4) yes plenty, I reckon I put about 1/4 litre on each floor.
5) I used cheap disposable paint brushes.
6) yes. I think you probably need to remove the tape before it hardens, just in case it takes the paint with it.
7) nope.

As usual, thanks Jon! I could've just asked you directly but wanted to give you a break 😂
 

moggy240

Insurance Valuations Officer
Staff member
Club Member
The panel you are priming needs to be clean and sanded for the primer to stick. You might want to wear a mask as that stuff has strong fumes or use in a very well ventilated area.
You could always use aerosol silver to save brushing it
 

Ashley

Club Member
Hi Robotsan

Just bear in mind the paint will still give off isocyanate fumes so be careful.
If you want a sharp paint edge, use fine line masking tape.
 

Robotsan

Club Member
The panel you are priming needs to be clean and sanded for the primer to stick. You might want to wear a mask as that stuff has strong fumes or use in a very well ventilated area.
You could always use aerosol silver to save brushing it

OK thanks. The floors currently have a couple of coats of Bilt Hamber Hydrate 80 rust converter on, so I should sand that a bit then? What kind of grit are we talking?

I've got a good new P3 respirator I use for all of this work so that should do.

Good point about the aerosol. I'd still have to do a lot of masking though. I'll think about it!
 
Last edited:

Robotsan

Club Member
Hi Robotsan

Just bear in mind the paint will still give off isocyanate fumes so be careful.
If you want a sharp paint edge, use fine line masking tape.

I'll definitely use the respirator then. And thanks, I'll grab some!
 

fae821w

Club Member
No isocyanates in epoxy primer, but obviously other nasties, I'm sensitised to one of the constituent parts. If you use polyurethane paints, which have isocyanates in the activators, you need full face air-fed masks to prevent absorbtion through the eyes.
 

Robotsan

Club Member
No isocyanates in epoxy primer, but obviously other nasties, I'm sensitised to one of the constituent parts. If you use polyurethane paints, which have isocyanates in the activators, you need full face air-fed masks to prevent absorbtion through the eyes.

Thanks. From my research it seems that the Lechler hardener does contain isocyanates though. See this data sheet: https://www.rsbikepaint.com/en-us/datasheets/2klaqactivator-msds.pdf

Says this on the first page:
1664209816628.png
So should I wear my proper goggles too? No harm in using the goggles and the P3 respirator.
 

fae821w

Club Member
That msds states its product number as being L0000174.

The Lechler epoxy primer states to use hardener 29370 or 29371.
 

moggy240

Insurance Valuations Officer
Staff member
Club Member
Personally I would remove as much of the rust converter as possible using 80 grit.
Epoxy primers work best on bare metal but can be used over previously painted surfaces that are sound. Having had previous issues with other rust converters I speak from experience.
 

Robotsan

Club Member
Personally I would remove as much of the rust converter as possible using 80 grit.
Epoxy primers work best on bare metal but can be used over previously painted surfaces that are sound. Having had previous issues with other rust converters I speak from experience.

Oh bollocks, really?! 😂 That's not great news!
 

moggy240

Insurance Valuations Officer
Staff member
Club Member
It's your choice, I did have a look at the data sheet for that rust converter and it says to do a test piece first so that seems to say it might be ok or might not. Technically it's not that critical as it is on the inside of the car.
I hope you have a heated garage as I was warned by the rep that it does not like being used below 15c as it affects its ability to fully cure.
 

Robotsan

Club Member
It's your choice, I did have a look at the data sheet for that rust converter and it says to do a test piece first so that seems to say it might be ok or might not. Technically it's not that critical as it is on the inside of the car.
I hope you have a heated garage as I was warned by the rep that it does not like being used below 15c as it affects its ability to fully cure.

Right ok, makes sense. I've been googling it and have found accounts of hydrate 80 flaking off the metal, although some say that's only if the prep wasn't good and if the 2nd coat was applied too soon. I gave it 24 hours so that should be fine at least.

But I think I'll sand some of it down first and see how it reacts to that. Then maybe try a test section as you say.

When you say it needs to be applied above 15°c, is that the Hydrate 80 or the Epoxy Primer? If the former, that's fine as it was applied when the weather was still good.

If the latter, then I'll have to get the heater I've got into the car to help cure the primer I guess.
 

fae821w

Club Member
Wouldn't worry too much about the need for heat, if using epoxy primer, all epoxy paints work on chemical reaction. Used these for 40 plus years whilst painting aircraft, including in unheated hangars and outside with frost on the ground. Ideally you want 15c minimum, as paint manufacturers state, but that's the beauty of epoxies when you don't have that. Air drying paints like acrylics and cellulose definitely need it to prevent "blooming" etc. I frequently had to ask our maintenance to turn on the boilers for heating our Paint Facility whilst painting overnight, even in June or July!!!
 

Robotsan

Club Member
Wouldn't worry too much about the need for heat, if using epoxy primer, all epoxy paints work on chemical reaction. Used these for 40 plus years whilst painting aircraft, including in unheated hangars and outside with frost on the ground. Ideally you want 15c minimum, as paint manufacturers state, but that's the beauty of epoxies when you don't have that. Air drying paints like acrylics and cellulose definitely need it to prevent "blooming" etc. I frequently had to ask our maintenance to turn on the boilers for heating our Paint Facility whilst painting overnight, even in June or July!!!

OK thanks that's good to know! :)
 

Robotsan

Club Member
I had a bit of a poke and a scrape at the rust converter and it seems extremely well adhered to the metal. Couldn't get it to flake or lift anywhere at all.

So I've just gone and keyed the whole lot with 80 grit and after cleaning it up I should be ready to prime it at the weekend I think.
 
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