Getting Started with Epoxy Primer

[Kent]

I make things out of mild steel. Normally most of these things live outside and therefore require a coating to prevent corrosion. I've been through a whole load of different things and they are all lacking in some fashion. To date I've been through:

• Rattle Cans (decent brand). Nice finish and easy peasy to use but have very little wear and salt resistance.
• Cold galvanizing paint (Galvafroid equivalent). Good protection from the elements but finish is very thick to provide the protection level needed. Also a total pain as it takes weeks to fully harden.
  
• Spray galvanizing cans. Absolutely 100% useless. Porous grey paint in a can.
• Powder coating. I had high hopes for this and it does do an excellent job; then a chip is made and the whole thing fails pretty sharpish from that point onwards.
• Enamel paints. They're modern enamels so more likely synthetics (I'm not great on the terminology as this is not my area at all)? Takes too long to reach full hardness and always seems to damage too easily. As I've got to do a few coats as well it makes it a job I don't look forwards to.
• Red oxide and aluminium phosphate. Don't know if I just have bad luck but these just seem a bit crap now compared to what I used years ago.

So I've been doing some research and there's a couple of ones that looked interesting: Etch Primer and Epoxy Primer.

The Etch Primer seemed to be the bees knees but I see that it's been replaced/superseded by Epoxy Primer these days so that's what I thought I'd go for. My problem is that I'm not 100% sure on whether I've found the right stuff, it's a decent brand and I haven't made any stupid or incorrect assumptions. Would SWK be kind enough to sanity check me here please?

I'm looking for something:

• That is hard-wearing.
• Suitable for coastal conditions.
• Final colour not really important providing it can be overcoated easily.
• One coat a definite bonus.
• Reasonable dry and (if necessary) re-coat time. Waiting 16h - 24h between coats is tiresome.
• Full cure in under a week, don't want something that takes forever to get properly hard (fnarr).

For application I will be using brush and roller. I do have a small compressor and some paint guns that I got from an auction but I have no desire to use them for this as I would imagine I am terrible at it. I also have absolutely no wish to get into what's needed to spray 2K safely for me and anyone or anything in the surrounding environment. Obviously I'll be wearing appropriate PPE for hand application but atomizing it just increases the risk to a level I'm not comfortable with.

I've looked about and there's a couple of manufacturers that seem to be respected, Lechler and HB Body. Through no other reason than I can get a kit from one and not the other, I have found the following and wanted to know if this is all I need to get started?

• https://www.ebay.co.uk/itm/182725586189
• https://www.ebay.co.uk/itm/132432560452

I assume I'll be needing thinners as I'm brushing/rollering. I remember Langy saying he diluted his Lechler 10 - 15% for rollering and if I could get my primer to look half as good as his I'd be over the moon. Is the dilution rate based on the mixed quantity or the primer quantity alone?

Also, can I overcoat with a rattle can (I use Plasticote which has an acetone solvent) to get a colour I want? I'm not bothered if the top colour gets knocked etc so long as the underlying metal protection is still in place. I see that tinting the primer can be done but as I'm just starting out with this I want to get the bare basics before I commit to anything extra.

When I mix can I use a flat ended blade as I would with a "normal" paint? Do I need to pass what I mix through a filter at all given I'm not spraying or is that another step to make sure everything's homogeneous?

Sorry for such a long post but this has been annoying me and stopping jobs for so long now I just want to get the right stuff and move on to the next job! Here's the item I'm going to be doing first, it's an electric/network supply adaptor box. Goes above ground right in the way where it'll get kicked and is subject to a lot of coastal spray (I'm about 500m from the sea). Constructed from 4mm mild and about the size of a shoe box.
View attachment 130466
Thanks very much if you can offer any help and apologies again about the essay

Snooch.

Why mskemit in ms 4mm ? Looks to me like
It mightmbe bebett in thinner stainless . Especially 500mtr from the sea.
Might answer the primer and paint thing in a different way

 

[optima21]

I'm using the Jotun 87 wintergrade and apply it with a brush without thinners. I bought some thinners but found it didnt make much difference. once mixed you have a couple of hours to use the paint. also the winter grade is mixed in a 1:4 ratio, so its a standard ratio on paint mixing cups.

 

[eSCHEn]

I'm using the Jotun 87 wintergrade and apply it with a brush without thinners. I bought some thinners but found it didnt make much difference. once mixed you have a couple of hours to use the paint. also the winter grade is mixed in a 1:4 ratio, so its a standard ratio on paint mixing cups.

Excellent thank you! First hand accounts are so very useful to me. I can get the paint and thinners (5L of Jotun 17) delivered for £81 but twenty quid in my sky rocket is better than someone else's

Do you just use brushes the once or wash them out with something? Lol if it's the thinners I have gunwash, would that suffice if I did it before the end of the pot life so it was still liquid?

Mixing cups - knew there was something else.

 

[steveo3002]

cheap gun wash cleans it up...although its sticky stuff so wouldnt blame you if you throw the brushes away

ive never bothered with thinners either ..flows out fairly nice on its own

 

[optima21]

I use brushes once and throw them away.....just leave them in the mixing cup and its gelled the following day. I use cheap 1" brushes between £0.25 and £0.50 each. the one use brushes tend to loose hairs though, but you can get "decent" cheap ones from places like home bargains. I normally mix between 150ml and 250mlk at a time. gunwash should be ok for cleaning brushes, but with the time to mix it, and cleaning up (if reusing brushes) you'll spend longer doing that than painting.

....and heres painting I did earlier with a paintbrush

 

[eSCHEn]

You sir, are an absolute legend!

Do you bother with the coffee filter type things or are they just for people who spray?

 

[optima21]

if you use a brush you're not going to get a mirror finish, so no I don't. |The paint is quite thick, so it would need to be a coarse strainer and then would take some time to go through. You'll also find that the epoxy primer separates in storage so its best to use a paint stirrer in a drill as it takes forever by hand.

 

[steveo3002]

yes what optima says , unless heavily thinned it wont go through a strainer , if you keep clean it shouldnt have any big bits in it , could put it through a cheap tea strainer if its full of lumps

get some disposable plastic drinking cups to mix in

 

[eSCHEn]

Thanks again Optima and Steve, I don't have local places to check this out in the flesh so I'm very grateful for the advice.

Jotamasic 87 ordered in Winter Grade Grey. I didn't bother with thinners and I picked up some 600ml scaled mixing cups and foam brushes. Should be here this week so if I can shake this flu off I can get a coat on this weekend

 

[steveo3002]

think you might want bristle brushes , its fairly thick

 

[eSCHEn]

I've got the standard assortment of brushes and rollers but wanted to give them a shot. Might be total dreck but they're cheap enough for the test and I've got something that definitely will work if they're no use at all

 

[eSCHEn]

Just my luck that the seller is out of stock when he went to ship it out lol. I'm not in a rush so am just going to wait for his delivery from Jotun as that way I figure I'm getting nice fresh stock

 

[ajlelectronics]

Or buy Lechler 29107 from Express Paints.

 

[eSCHEn]

Or buy Lechler 29107 from Express Paints.

Given how much information I've pumped into my tiny addled mind about Jotamastic 87 in the last few days I'm going to stick to my guns for now

 

[Burdekin]

87 is a good choice for what you want. It will adhere better than pure epoxies and other coatings so if you aren't media blasting then is a good choice, good corrosion resistance and pretty tough.

Not sure if it makes much difference but Jotun don't recommend using a roller for the first coat.

 

[steveo3002]

yes its a top choice ...and good that youre getting brand new stock

 

[eSCHEn]

No my prep is thorough but all by hand. Hot citric acid bath to loosen millscale then scrubbed with red scotchbrite under water. Rinsed and then re-scrubbed using a paste mix of bicarbonate of soda and water to neutralize the acid. Stored at < 3% RH (the lowest my meter will go) at ~25°C and no flash rust seen. This is the second time I've cleaned this thing up. Like I say, I really don't like painting and I'm not good at it either so I've been putting this off for a while now

Edit - yes I saw that in the AG about rollering the first coat. I think brushes will work better for me on this as it's an awkward shape.

 

[Burdekin]

These are good for hand prep with the grinder, but need to watch them as they do bite and lose the occasional wire. https://www.screwfix.com/p/titan-twist-bevel-100mm-brush/64592

 

[eSCHEn]

They are the spawn of the devil, and that's being as kind as I can to them

Their purpose in life seems to be to embed themselves in whatever is most annoying or painful (preferably both). I do use them but only when I absolutely have to

Still, not as bad as the die grinder I suppose...

 

[slim_boy_fat]

Their purpose in life seems to be to embed themselves in whatever is most annoying or painful (preferably both).

That can include the front of your jumper [ask me how I know.....]