Bike frame primer?

[Cato]

Whilst I see and understand the point you are making; on a 'bike frame, you would only use about 250mL, the rest will last for years. You could even brush it if you had no spraying facilities. Even so, a primer gun isn't going to cost a lot and cleaning is pretty straight forward. That aerosol is scrap an hour or so after opening, regardless of how little has been used and you have to buy another next time you want some.

Bare frame, two spoked wheels, two brake hubs, swing arm and the tank all bare metal stripped, so I reckon half a litre will be about right as everything to be primed will be ready. Then I can get a couple of aerosols of the NATO green, as Military stuff isn't exactly renowned for the perfect paint finish. The main reason for not using a brush are the wheels, I think I'd lose the will to live before I got half way on the first one.

Any other bikes I do will need to be sprayed properly i.e. not by me. So without doing another bike like this I'd have no further use for a spray gun otherwise I'd agree and get a gun etc, set up a spray tent/booth with polythene when needed and have the associated consumables.

 

[ajlelectronics]

250ml is mixed 2:1 + 10% so there is your 400ml.

 

[Wildefalcon]

Surely you wouldn't choose zinc phosphate over 2k epoxy. I've used zinc phos, it's very good but 2k epoxy is on another level.

I'm curious, why not just use 2k epoxy zinc phosphate?

 

[striker]

I'm curious, why not just use 2k epoxy zinc phosphate?

Is there such a thing?

 

[minimutly]

That is +2k+ paint in an aerosol. You pull a tab to release the hardener into the paint just before use. In a couple of hours, the whole lot goes hard. Your response only applies to air dried paints.

Ahh, new one on me that one. You learn something everyday on here.

 

[Ross365]

Is there such a thing?

Is seems there is. I was looking at alternative single pack zinc phosphate (ZP) paints tonight when I'm pretty sure a 2k option turned up. Given that all polymers have measurable permeability to water, it always seems to me that a paint with corrosion inhibiting chemicals in it will be better than one that hasn't. But it's complicated; the thicker the paint, the more protective it is. But if you complied a list of selection criteria for choosing a paint, there will be trade offs. For use by "amateurs at home", 2k isocyanates look a bit off-putting to me. However, an alkyd (single pack) ZP phosphate primer needs 12-16 hours before you're supposed to overcoat, so that's off-putting too, but in a different way.

One of the things I really like by about alkyd ZP is how well it wets the surface of anything it touches and disappears into seams. It's great for the underside of a car when you've only got it on axle stands. Is anyone a fan of micaceous iron oxide paint ? Supposed to be good because the effect of the micaceous flakes is to greatly reduce the permeability of water through the paint (for a given thickness).

 

[graffian]

Get the blaster to paint it?
There was someone on one of the land rover forums who worked at a blasters and
a lot of the stuff got sprayed with micaceous iron oxide after blasting, so all his
landrover parts got done like that and he got good results.

 

[Wildefalcon]

Sigmafast 205 is a 2k non iso zinc phosphate epoxy. eBay.

 

[ajlelectronics]

All epoxy 2 part primers are non isocyanate as far as I know.

 

[Cato]

Get the blaster to paint it?
There was someone on one of the land rover forums who worked at a blasters and
a lot of the stuff got sprayed with micaceous iron oxide after blasting, so all his
landrover parts got done like that and he got good results.

They don't do paint unfortunately, just powder coat.

 

[Keithmac]

I'm using Mipa EP 2k Epoxy primer on my Golf restoration.

 

[8ob]

Non sand primer? Cant say I would relish the thought of rubbing down a bike frame or hubs

Bob

 

[Cato]

Non sand primer? Cant say I would relish the thought of rubbing down a bike frame or hubs

Bob

Whatever it says on the tin it will be non sand I assure you. Stuff that for a game of soldiers!

 

[Ross365]

OK, so isocyanate 2k paints are going/gone, but even with that being so, what are the negatives of using 2k paints, esp for someone who has not used them previously and is working at home? Play nicely and be objective please

Regarding 1k zinc phosphates (ZP) ( and this could be true for 2k) it seems that the quantity of ZP in them can vary a lot. Mostly, the data sheets say ~1%, but there is one company (Coo-Var) says 5-10% . As the ZP is used up during the life of the paint in chemical reactions inhibiting corrosion, I think this is must be important.

 

[ajlelectronics]

OK, so isocyanate 2k paints are going/gone, but even with that being so, what are the negatives of using 2k paints, esp for someone who has not used them previously and is working at home? Play nicely and be objective please

You need to differentiate between 2K paints. 2K is German, Zwei Komponent which tells you that it needs mixing with a hardener. It doesn't tell you anything about that hardener though. Epoxy primer is a 2K but it does not use Isocyanates in the hardener, therefore it is safe to spray or brush with standard PPE and air fed is not a requirement as it would be with Isocyanate hardeners.

I can't think of any negatives for 2K epoxy primers, only positives. I suppose if you want to nit pick, you could mention the 24 hours before sanding, but that's it. The stuff is not even expensive!

Regarding 1k zinc phosphates (ZP) ( and this could be true for 2k) it seems that the quantity of ZP in them can vary a lot. Mostly, the data sheets say ~1%, but there is one company (Coo-Var) says 5-10% . As the ZP is used up during the life of the paint in chemical reactions inhibiting corrosion, I think this is must be important.

Yes, I understand that Jotun epoxies have specific zinc laden paints, marked as such. I only use automotive grade primers like the Lechler 29107 so @Burdekin etc may be more knowledgable than me about that product.