Weird finish from tamiya metal primer

[panzershreck]

Hi everyone
I have some issues with the application of tamiya metal primer over the metal parts and I am hoping someone can help me out on this.

I applied tamiya metal primer to the metal parts over 2 days and I got very inconsistent effects on the cast steel parts and the aluminium road wheels.

During the first session, which was a warm and windy day, the primer appeared to have no visible effects over the metal hull, cast sprockets, idler wheel and suspension arms. It seem as if I didn't apply any primer at all.

On the 2nd session, which was in the shade and less windy, I applied primer from a new can on the remaining metal parts, the road wheels and barrel. This the outcome. At first I thought I didn't cover some areas but every road wheel had the same issue and it didn't go away despite applying a 2nd coat.

[HERMAN BIX]

Looks like the pigment has compacted in the can & only the solvent and a tiny bit of pigment has made it onto your parts.
Tamiya primer is not a true self etching product. Its a primer by way of surface preparation with a bit of extra solvent.
But its not a real hard core surface penetrant like that used to undercoat fabricated steel.
I carry the primer around in a pocket of my cargo shorts for ages before I use it.
Warms to body temp and is constantly shaken.
The stuff I use has a ball bearing in it to aid in mixing prior to spraying.

[jarndice]

I always use Mr Hobby in a small bottle and brush it on, I have never had a bad reaction on any metal surface, Just a quick shake and it just lasts forever,
Highly recommended
Shaun.

[43rdRecceReg]

Can't you just used grey or red-oxide rattle can primer from Halfords? I've also used Humbrol grey primer (also rattle can) on metal with success. Tamiya metal primer is pricey, and hard to get hold of.
I'd also abraid the metal surface slightly, and clean it of any contaminants if I were you (protective coating, for example). Ideally, there should be little on no breeze and the metal surface should be reasonably warm for the spray to settle without rapid shrinking (i.e no yawning difference between the air temperature and that of the metal surface..). Also, as HB has suggested (it's often written in the instructions too), warm the can well,then shake rattle and roll it before use. Finally, invert it for a short blast to clear the nozzle after each use..

[jarndice]

Hi, Roy, Having had a bad reaction to spraying Simoniz red oxide on to a metal fender, That was when I began using "Mr Hobby" Metal Primer first on every metal part, and then the Simoniz Red Oxide spray,
But as you say preparation is everything,
I never fail to wipe over everything that is getting painted with Acrylic thinners first,
I don't buy TAMIYAS own Instead I buy a 1 litre can of "Servisol" Isopropanol, (Acrylic Thinners) for 1/4 the price at £15 a Litre from Maplins versus £9 for 250ml from Tamiya
Shaun.

[panzershreck]

Looks like the pigment has compacted in the can & only the solvent and a tiny bit of pigment has made it onto your parts.
Tamiya primer is not a true self etching product. Its a primer by way of surface preparation with a bit of extra solvent.
But its not a real hard core surface penetrant like that used to undercoat fabricated steel.
I carry the primer around in a pocket of my cargo shorts for ages before I use it.
Warms to body temp and is constantly shaken.
The stuff I use has a ball bearing in it to aid in mixing prior to spraying.

So i need to spray another brand of primer on it?

Does this mean the sprockets which had an invisible finish is ok?

[Rad_Schuhart]

Looks like the pigment has compacted in the can & only the solvent and a tiny bit of pigment has made it onto your parts.
Tamiya primer is not a true self etching product. Its a primer by way of surface preparation with a bit of extra solvent.
But its not a real hard core surface penetrant like that used to undercoat fabricated steel.
I carry the primer around in a pocket of my cargo shorts for ages before I use it.
Warms to body temp and is constantly shaken.
The stuff I use has a ball bearing in it to aid in mixing prior to spraying.

So i need to spray another brand of primer on it?

Does this mean the sprockets which had an invisible finish is ok?

I think it means you need to shake your can well (you should heard something inside making big noise) because the primer is grey and I think is compacted at the end of the can and you are spraying only gas.

Or you can buy another primer from the recomended ones, but again you need to shake it properly.

[panzershreck]

Looks like the pigment has compacted in the can & only the solvent and a tiny bit of pigment has made it onto your parts.
Tamiya primer is not a true self etching product. Its a primer by way of surface preparation with a bit of extra solvent.
But its not a real hard core surface penetrant like that used to undercoat fabricated steel.
I carry the primer around in a pocket of my cargo shorts for ages before I use it.
Warms to body temp and is constantly shaken.
The stuff I use has a ball bearing in it to aid in mixing prior to spraying.

So i need to spray another brand of primer on it?

Does this mean the sprockets which had an invisible finish is ok?

I think it means you need to shake your can well (you should heard something inside making big noise) because the primer is grey and I think is compacted at the end of the can and you are spraying only gas.

Or you can buy another primer from the recomended ones, but again you need to shake it properly.

I did shake the can..probably not long enough.
maybe i should get another brand instead.

[Jake79]

I use this stuff, cheap and never had a problem with it..

http://www.ebay.co.uk/itm/2x-HYCOTE-XUK ... 2183482917

[HERMAN BIX]

I only use a genuine self etching primer, happens to be in red oxide.
Any alleged primer that is not self etching is a surface prep rather than a primer.
It wont have the grunt to actually eat its own bond into the parent material.

Yes, shake the bejeezus out of the can and at body temp not 8 degrees C like you poor buggers have up there at the moment !
I also find that with my primer at least, warming the subject with a hot hair drier is an added help(in winter)

Clean the surface of the subject material, and warm the paint and subject.
Should be no further problems