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BUSBOSS Thu May 12, 2016 12:06 am

Anyone have any tips for painting the black pulley while attached to the fan?


chrisflstf Thu May 12, 2016 7:53 am

Masking tape, paint

beetlenut Thu May 12, 2016 9:55 am

Unbolt it from the fan? Maybe add some more info to your question.

BUSBOSS Thu May 12, 2016 11:33 am

Thanks for the suggestions so far.

The fan can't be unbolted because it will destroy the factory set balance. Many have tried this with disastrous results and consequences.

Old fashioned masking may be the only way but boy is that labor intensive with all of those fan blades.

57BLITZ Thu May 12, 2016 12:05 pm

Set the pulley into a shallow pan . . . fill the LEVELED pan with properly THINNED paint up to the level of the fan . . . remove pulley from paint and carefully hang to drip-dry.
I suggest some of this . . . http://www.lowes.com/pd_282851-90-243995L___?produ...ance+black

BUSBOSS Thu May 12, 2016 1:26 pm

Now we are getting somewhere. Let me look at the lip of the pulley to see if that will solve the problem. Thanks.

Keep 'em coming.

chrisflstf Thu May 12, 2016 3:44 pm

If balance is the issue and it is balanced already, why cant it be marked to properly reorient it ?

BUSBOSS Thu May 12, 2016 4:01 pm

chrisflstf wrote: If balance is the issue and it is balanced already, why cant it be marked to properly reorient it ?

I agree that ut sounds reasonabke enough. But like many things, it sounds easier than it is in reality. Many have tried that exact approach with limited success and all have regretted it. I will try to find the link for the relevant thread in the Bay Windows forum and post it here.

BUSBOSS Thu May 12, 2016 4:21 pm

Here is just one thread on the subject. You will see I posted my paint question there as well.
http://www.thesamba.com/vw/forum/viewtopic.php?t=628719&highlight=fan++balance

raygreenwood Thu May 12, 2016 4:26 pm

Its not a balance issue at all.
It CAN be if you do not reassemble it with the same bolts going into the same holes and the same holes....pulley to fan....matching up.

In other words.....if you change clock position of pulley to fan casting.....you will put the factory balance weight one or more quadrants out of whack. The balance weight....if it needed one and has one (not every fan has one).......is crimped under the rolled edge of the pulley.

The REAL problems people have....are that the bolt holes in the pulley are about .015" to .020" larger in diameter than the bolts......so if you unbolt it.....its exceedingly difficult to get it back in the exact postion....so it runs out of round because the pulley gets installed off center.....the problems it causes are throwing belts, working bolts loose and if its bad enough....it can crack the fan. Ugly vibrations.

Its also not that hard to work around. I have used two different methods.....both will allow the fan to reassemble to within .001" maximum deviation if not spot on to factory.

1. On a workbench, make yourself a flat work board out of a piece of flat 1" thick MDO board.
Cut a center hole that fits the crank hub tightly.
Mount the fan with its hub attached. Make sure the hole in the board is tight enough that you have to tap the fan in lightly.

Mark on the board where TDC is on the fan so if you have ro pull it off the board it goes back on the same way. You should not have to pull it on or off the board more than once or twice.

Get some steel threaded hex couplers, some small steel straps about 1/8" thick and 2" long...and bolt the couplers to the board. I used 5/16" thread with captive panel board nuts on the back of the MDO board to screw them into.

Mount these three posts 1" away from the fan. Be accurate. Use a compass and draw a circle
Mount the threaded coupler posts at 120° apart.

On the top side.....drill 5/16" holes in the steel straps 1/2" from one end and 1/4" from the other.
I bolt cheap 608ZZ skate bearings to the end of the strap that is drilled 1/4" from edge.

Bolt those to the top of the three hex couplers.

You now have a precise jig. Mount the fan in the center hole. Make sure it is tight in the hole.

Take the three levers and bring the bearings on the ends up against the edge of the pulley tight.....at all three points 120° apart. Lock them tight with their bolts to the hex couplers.
Check your work. Mark the coupler end to the strap with a sharpy just to be sure you dont move anything.
Now...lightly tap the fan out from the back of the board. Lift it straight out.

You can now disassemble the fan and paint the pulley.
On reassembly.....place the fan in the jig. Lower the pulley in between the three bearings and first finger tighten, then cross torque and the final torque. Done.

This is the first way I did this. I have done 4 fans this way. No issues.

2. The simpler way....but you have to be careful.....is to remove one bolt at a time.
About 1/8" away from the bolt hole. Carefully drill....with a 1/32" drill bit with a drill stop on it.....a hole....through the pulley and into the aluminum of the fan. It only needs to be .125" deep.

Put that bolt back in and lock it down.....and repeat this for all four bolts....one at time.
All four holes need to be the same depth, and placed in the same direction offset from the through bolt hole.....in this way there will be no balance change. You really only need to drill two holes 180° apart for alignment.....but drill all four posts just to keep things even....balance wise.....even though you are looking at only about 1/100th of gram change....why risk it.

Now.....remove the bolts and paint the pulley. For reassembly....insert a 1/32" dowel pin in each hole you drilled. Remove one pin and install the bolt and nut and tighten lightly....making sure none of the dowel pins have side load on them.

Go to the bolt hole 180° from the one you just inserted and repeat the process. Tighten those first two bolts and torque them.
Check to make sure neither of the remaining two dowel pins has side load on them or are stuck. If they are...loosen the first two bolts and repeat until this is right.
The fan is now locked safely to the pulley. Remove the other two pins and insert and tighten the bolts.
This 2nd method is much easier....but you need a good drill bit.....and preferably a drill press and you need to be confident and meticulous in your work. Outside of that its about 30 minutes of work.

Ray

modok Sun May 15, 2016 1:23 am

I'm quite confused.
For one thing, the pulley does appear to be painted gloss black currently, and the fan isn't, so how did that happen? Did you get this thing out of a time capsule? It must be a rare OEM NOS fan if it's never been used on the engine since painted and then balanced in germany, and the paint sure looks good given it's age LOL Who you foolin?

second, it's not ready to paint, so, you need to prep. You can't just paint over gloss paint and expect it to work.

Third, why is overspray on the fan a problem?

So, is this a trick question?
Or are we supposed to guess how YOU painted it?
ah, is that it? no, probably isn't.

Ok, perhaps the picture is just an example of a fan.
Just bead blast the whole thing and paint the pulley, and if you don't like over spray on the aluminum, then.....paint the whole thing. Why not? powdercoat the whole thing! there you go, that's actually doing some good.
If you don't like the look of that, then paint the inside of the fan aluminum color.......ok that was a joke, but it would work :P

dirtkeeper Sun May 15, 2016 10:08 am

A nicely cut round piece of cardboard should fit in the middle and wrap the outside with tape

raygreenwood Mon May 16, 2016 8:18 pm

I have seen the picture before. I dont think it was his picture.

I think the gist was....how to get hos fan to look nice like that one again.

And...for those who dont know.......if you powdercoat a type 4 fan...you will generally have to get it rebalanced....in the worst case.....but the usual issue is being very careful to mask the rear coupling area where it mounts to the hug.

Any bit of overspray in that area affects how flat it sits on the taper hub. Been there,

Unlike a type 1 fan...because this is attached to the crank on a morse taper ...and its a little different than a type 3 fan....if it gets far enough out of balance it destroys itself...eventually. Sometimes quicker than you think.

The usual problem ...as I mentioned...is not balance though.

The poor diligent unknowing newby owner will note the balance weight position relitive to the sector that contains timing marks...and take it apart to paint and clean....and slap it back together.....not realizing that it will easily be anywhere from dead on to .015" out of round at the pulley.....which screws things up badly. Ray

chrisflstf Tue May 17, 2016 7:48 am

I would think you could get it back to concentric by mounting a dial indicator on the outer edge and spin it. Measure and adjust till its back to near zero

BWingate Tue May 17, 2016 10:57 am

dirtkeeper wrote: A nicely cut round piece of cardboard should fit in the middle and wrap the outside with tape

This or paint the outside black first then mask the black and paint the silver fins

raygreenwood Tue May 17, 2016 8:33 pm

chrisflstf wrote: I would think you could get it back to concentric by mounting a dial indicator on the outer edge and spin it. Measure and adjust till its back to near zero

Yes....and you will need two tapered live centers....and that only works on the early 411/412 fan after you pop out the center dome plug.....or a VERY large diameter live center for the later fans and its a difficult fit and it takes a LONG time... and its not as dirt simple as it sounds....but sure you can do it that way.

As I noted....there are several ways....all of which work. Ray

raygreenwood Tue May 17, 2016 8:34 pm

BWingate wrote: dirtkeeper wrote: A nicely cut round piece of cardboard should fit in the middle and wrap the outside with tape

This or paint the outside black first then mask the black and paint the silver fins



Paint on that fan is very short lived....depending on how much dust is in your local air. Just clean it up...maybe polish it....or yes....powder coat it. Ray

modok Thu May 19, 2016 4:53 pm

Forgive my lack of appreciation, but I feel I should express it.
BLAST, PAINT, done. Was the dirt helping to balance it? I think the amount of dirt on most fans is more mass than the paint, so, it should be MORE balanced once cleaned and painted.
To make the paint even, spin it while you spray :P How to do that? figure it out man! use what you have available to you.

Build a show car or a go car, don't do both, it's too much work

Powder coating, done WELL, gives a more even thickness than can be achieved with paint. done right it is really amazing, but I've seen it done...not so great too. In fact, the shop I used that did great work.....is no more, and, the others I've used, suck. SO, Now I use paint. SKILL it's real. Done right it will work. Done wrong it won't. The secret is, there is no secret. The secret is skill

You could install 1/8 locating pins before taking it apart too, or take out the bolts one at a time and ream the holes as you go, and use those as location. You could do anything, and if you do it right, it will work!

raygreenwood Thu May 19, 2016 8:17 pm

modok wrote: Forgive my lack of appreciation, but I feel I should express it.
BLAST, PAINT, done. Was the dirt helping to balance it? I think the amount of dirt on most fans is more mass than the paint, so, it should be MORE balanced once cleaned and painted.
To make the paint even, spin it while you spray :P How to do that? figure it out man! use what you have available to you.

Build a show car or a go car, don't do both, it's too much work

Powder coating, done WELL, gives a more even thickness than can be achieved with paint. done right it is really amazing, but I've seen it done...not so great too. In fact, the shop I used that did great work.....is no more, and, the others I've used, suck. SO, Now I use paint. SKILL it's real. Done right it will work. Done wrong it won't. The secret is, there is no secret. The secret is skill

You could install 1/8 locating pins before taking it apart too, or take out the bolts one at a time and ream the holes as you go, and use those as location. You could do anything, and if you do it right, it will work!

Mostly true. .. :lol: .....I also agree about the paint instead of powder coating. There are so many fantastic paints these days with great chemistry. Hardly any need for the hassle of powder coat.

The problem with these fans is that without serious,cleaning and prep....paint does not stick to tha aluminun well. The hub is nearly a press fit so the back side is just good masking work.

The pulley is steel. .....masking between the fan and pulley to paint. ....is actually a lot of work on this fan....if you care how it looks. If not....then its no big deal. But as the overlapping paint on the aluminum peels off.....it starts peeling the pulley edges.

This is why people get anal about trying to get this thing painted.

The problem is that the unknowingly anal newb......makes the mistake of disassembling the pulley from the fan without any of the afore mentioned locating methods......and without some thought or practice. .... its a bitch to get back together without a hideous vibration.

As I mentioned.....imbalance is usually not the issue. Getting the pulley back on concentric to the fan is the main problem.

I am sure it was a typo....and I agree pins are the way ro go....but there is no place anywhere to put 1/8" pins. 1/32".....just for location is all you have room for on the four support fins.....but thats the simple way to go.....pull 1 bolt at a time on a fan that is known to be concentric.....install a pin next to the bolt. ....and its done. Ray

modok Thu May 19, 2016 11:54 pm

no place for little pin? ok, you'd know better than I, I was just brainstorming.

If you dip it in paint, then spin it, will it balance itself??
HA!



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