Lechlar Primer - temperature sensitivity

[rtcosic]

Finally bought some of the much recommended Lechlar epoxy primer for BRUSH application.

The hardener is labelled 25-35 deg C. If that's real I'll never be able to use it! My garage is around 15deg C. It can take a few days to 'harden' as I'm in no rush. Can I use it or do I have to wait for a heatwave?

 

[fizzy]

Most normal epoxies are ok from about 10C up and 85% humidity max. Watch the humidity - Wales in winter is often over that.

Keep and mix the materials at room temperature.

 

[Dcal]

As @fizzy says get the paint / hardener and if possible, the part inside to get them up to room temp, or keep them in a box or under a sheet with an electric heater to take the chill out of them.
Paint the part, let it get touch dry then back under the sheet with the heater and let it cure.

I don't recommend taking the part inside until it is fully cured unless you have a very understanding better half.
It will give off fumes until it's fully dry.

 

[rtcosic]

Thank you both. No problem making a little tent and sticking the fan heater in there. Done that before when painting parts with enamel over a previous Christmas break. Accidentally made a mini sauna in the shed.

I'll check the humidity, but it should be fine. There is an humidity switched fan in the next door utility room set at 65% and that rarely comes on automatically.

I have been chastised for curing painted brake calipers in the oven before, so I have no desire to go there again.

The scars are barely visible now.

 

[Dcal]

The humidity needs to be really bad (like dripping off the walls) before you will have issues.
Epoxies are very forgiving but it's always good to give any paint job the best conditions you can.

 

[ajlelectronics]

The humidity needs to be really bad (like dripping off the walls) before you will have issues.
Epoxies are very forgiving but it's always good to give any paint job the best conditions you can.

Yes. I have used Lechlar in 10C etc it just takes longer to go off and is thicker to spray.

 

[Mikey D]

Timely thread as I'll be using lechlar epoxy rollered on tomorrow for the first time will rig up a tent and heater

 

[rtcosic]

Timely thread as I'll be using lechlar epoxy rollered on tomorrow for the first time will rig up a tent and heater

We'll compare notes then, maybe even PHOTOGRAPHS!

 

[Mikey D]

Ahh my harder is labelled 5 to 25 degrees epoxy primed fast

 

[Dcal]

I'm just going out to spray epoxy and top coat, I should have photos in the "show us your welding cart" thread tomorrow.
So we should have brush, roller and spray to compare.

 

[RaceDiagnostics]

Looks like you bought the wrong harder, I use 29371 which is for 5 to 25 degrees. Call the supplier and ask if you can change it.

 

[ian f]

brush painted some parts over christmas. spread the epoxy out really thin for the first coat which was touch dry after about 10 mins then a couple of heavier coats then next day a quick rub over with 180 grit and then 2k brushed on leaves an ok finish

 

[Dcal]

Got the epoxy on my cart, it's started out as an old fire extinguisher station that was really too lightly built and a lot of rust scrap I had laying about so it's a real mess.
I should have sandblasted it but as it will be living inside I just gave it a rough grind down and a quick sanding.

Tools used and one badly sanded cart



And after a couple of heavy coats or Jotun 87A applied with a cheap gravity gun with a 2.5mm fluid tip.



It's pretty rough (I was trying to cover a multitude of sins) so I might have to give it a quick rub down before applying the top coat.
No heat or anything required, it amazingly warm here for this time of year.

 

[Dcal]

brush painted some parts over christmas. spread the epoxy out really thin for the first coat which was touch dry after about 10 mins then a couple of heavier coats then next day a quick rub over with 180 grit and then 2k brushed on leaves an ok finish View attachment 205689 View attachment 205690 View attachment 205691 View attachment 205692 View attachment 205693

Really nice job.

Did you thin the paint after mixing with the hardener?
I've never tried brushing 2 K but with results like that it would be a well worth doing.

 

[Mikey D]

brush painted some parts over christmas. spread the epoxy out really thin for the first coat which was touch dry after about 10 mins then a couple of heavier coats then next day a quick rub over with 180 grit and then 2k brushed on leaves an ok finish View attachment 205689 View attachment 205690 View attachment 205691 View attachment 205692 View attachment 205693

What topcoat did you use ,I didn't think u could brush 2k (apart from epoxy ) ??? I know very little about paint tho !

 

[Mikey D]

Just done two coats this evening , foam rollers don't get on with it tho was doing in in my part finished shed , had to block up the gaps with celotex to keep the heat in , ironically it's the doors I'm painting

 

[Dcal]

Short pile rollers are better for anything volatile but the foam ones might just last long enough of you are only doing small bits

Got the top coat on my cart, had to give the 87A a bit of a flat.
It will do for what it is.

 

[Mikey D]

Looks good Dcal what did you use for topcoat ?

 

[minimutly]

brush painted some parts over christmas. spread the epoxy out really thin for the first coat which was touch dry after about 10 mins then a couple of heavier coats then next day a quick rub over with 180 grit and then 2k brushed on leaves an ok finish View attachment 205689 View attachment 205690 View attachment 205691 View attachment 205692 View attachment 205693

Ooo, mini bits!
They never looked like that from the factory, one coat should have done it?

 

[graffian]

Ooo, mini bits!
They never looked like that from the factory, one coat should have done it?

I looked at them and thought, there's familiar.

So you don't recomend a roller to paint the bottom of my petrol tank, I don't want to wait
till the weather is better so I can spray it outside. Langy did tell me about using foam n 2pack,
not that I can remember what he said, I think it was along the lines use a roller not foam?