drying problem

[hbdub]

Good morning all i am a new member here. i came across this forum after googeling spray techniques and came across the very helpful tutorial.

i have a slight problem with my paint drying, i am refurbing a set of alloy wheels and i have done all the necessary
1.rubbing down
2.filling in parts of the wheel
3.rubbing down
4.cleaning, drying, tac clothing the wheel to remove fibres
5.heating wheel in an oven for 10/15 minutes using a 1000watt infrared lamp in a sealed metal box.
6.Prime the wheel put back in oven for 5 mins
7. leaving to dry overnite.

My problem is i came in to wet sand the primer this morning and the paint is still wet, i can handle the wheel but if i dig my nail in it digs in. also when i sand it the paint is coming of and sticking to the paper. any clues on what may have done wrong? i am using a cellulose primer mixed with a hardener at 60/40 ratio. i have placed the wheel back in the oven at the moment to see if this will help.

Please can someone help me on this, thanks in advance
H

Ps it was raining yesterday as i was spraying (under a shelter) but the wheel was piping hot.

 

[pedrobedro]

Cellulose I've used has thinners not hardener. Clean them off and paint them again with the paint with ordinary thinners in it.

 

[steveo3002]

yeah something wrong there...celly primer doesnt use hardner

also...celly primer isnt much good on alloy , you should idealy etch any bare bits first

 

[Alfaman]

Yep,

I've used UPOL acid etch #8 on bare alloy wheels in the past, works very well indeed. Then a high-build primer before applying the topcoat.

I'm not sure about having the wheels that hot, though. Are you sure this is necessary?

 

[hbdub]

hey guys thanks for the replys, i asked someone else too and hardener is for the 2k paint only. as you guys can see im a novice at this and just getting into it. i have now taken off all the primer and getting ready to re primer using a thinner instead. if i use etch primer do i have to wet sand it back b4 i apply a filler primer.....also just another quick one while im at it. is wet sanding the primer necessary b4 the colour coat?

thanks again people

 

[hbdub]

Oh yeh im heating the wheels because its very cold where im spraying and the wheel takes in moisture so ive been told.....this will help with the drying process

 

[BillJ]

It sounds as though you need to read this thread before you go any further:
http://www.mig-welding.co.uk/forum/showthread.php?t=14051

2K hardener is very dangerous stuff and if you've been heating it you're likely to increase further your exposure to it. What protective equipment have you been wearing?

 

[hbdub]

just a 3m mask....thanks for the link i will have a read of that.

edit: just read the top post and has shocked me, i do spray outdoors in a shelter though

 

[pedrobedro]

Acid etch only needs the lightest of dust coats, you can get aerosols which will do your wheels easily and will cost a lot less. A good coat or two of primer over it will give you something to rub down.

 

[Chipper]

Get that celly+hardener all off, etch the bare metal. Maybe wipe it off with thinners, rags etc? Save sanding.
Warm is OK, but would've thought not hot, you want the paint to have a chance to flow out and bite etc. Celly dries PDQ anyway so no need for anything too extreme.

Dry sanding primer's better, primer'll soak up moisture. There's a 3m paper called "Fre-cut" thats brill for dry sanding.

 

[hbdub]

Thanks to everyone who has helped out by replying today on this post. this forum is EXTREMELY helpful. thanks you all again H

 

[jaykay]

glad you dont mix my drinks.lol.
clean all the primer off.
etch,high build primer topcoat.
a1 to freecut

 

[h-magic]

Do you have to really Etch primer the wheels?
Can you not just use 2K HS primer?

 

[steveo3002]

have to etch bare alloy if you want it to last

2k will go on there no probs. but it will fester and lift off fairly easy

 

[h-magic]

Oh dam. Great wish I knew well not to late.
Still got three to go.