Wednesday, January 11, 2012

Custom painted forks...it's in the details

Time has been passing quite fast around the shop.  I've had a number of projects in the works, but nothing that I felt especially compelled to share, as much of the processes have been detailed ad nauseum here in the past. I have had a few other builders email, wanting to know the best way to paint a suspension fork to match a frame...is it better to fully disassemble it, paint it and rebuild, if not, how do you mask it to insure full coverage without leaving any tight areas unpainted?

I've been waiting a looong time for a shipment from Fox to arrive, like months.  It seems if you do not want a trendy tapered steerer it has to be custom assembled, then year end inventory hit, then the Holidays shipping barrage, excetera excetera.  Now that they are finally here, one of the forks is going on Dave's bike.  Since the time lines have converged with the location of the show being very close to Dave's home turf, this one is gonna be in Sacremento, so I offered to paint it to match to give the bike a finished look.

I've painted a lot of sussy forks from all the manufacturers, some are easier to disassemble, some better to paint fully together; Fox falls in the latter category due to the necessity of replacing seals, tight tolerances during assembally that can mar your finish, and overall shape.

So, to get ready, the first item on the adgenda is to strip her of all the decals, wipe down with degreaser, and then sand the powder coat finish with 600 grit paper to give the base layers some mechanical grip for the coming colors. 
Once sanded, it's time to spend some quality time taping everything up.  I spend about a third of the total time it takes to paint a fork in taping prep, as the close tolerances are critical to the finished product.  Starting with the seals, I carefully place 3M thin blue line around the edge, pulling with just enough tension to nestle it down to the base level without stretching it.  To get in behind the brace, I use the tip of a sharpend spoke to gently push it down into place before applying tension to each side to set the adhesive.

The blue line is then covered with a wrap of Scotch Green mask tape, being careful set it just above the lower edge, then closing it up at the top.

Blue line goes at the top of the stantion tube, then green mask in the same process, then the stantion is covered in green tape to preserve it's coolio finish.

The top caps need to be unthreaded a turn or two, allowing just enough space to allow for a piece of blue line to pull under the edge, enabling just enough spray to get under the cap but not against the threads.  Yeah, takes a bit of practice to get it just right.  I raised it a bit here in the picture to illustrate, turned it down one notch before continuing.

 I then grabbed the calipers, measure the diameter of the inner contact points for the axles, and cut some happy little vinyl circles to mask off for the hub and thru axle areas.  More blue line and green tape over the lower knobs and a rubber plug to protect the threads of this little hole.


 Next up, it's time to shoot our color layers.  Here the base pink is applied.  You need to work the paint into the area between the stantions and the brace very carefully, turning down the inlet pressure and lightly fogging in the product from both lateral aspects to get even coverage.  Too much pressure or paint and you'll get a runny mess on the edges that will be a bear to clean up.
 For the next step, I made a little custom stencil out of some nylon hair and some vinyl tape.
 I then methodically went over the whole fork, overlapping my hairs, spraying through the stencil with an airbrush to create the darker pink overlay.
 Some more time with multiple airbrushes and some custom cut stencils gives us the cheetah spots...here is our fork with the work all sealed under a layer of clear.
 An after two more coats of clear with some intermittent sanding, dry time, and some careful mask removal, we have our matching fork.
Some tips on removing your masking...

In the small/tight detail areas like the blue line tape, it is easy to tear set paint away if you do not meticulously pull the tape back over it's self 180 degrees, so that it cuts the tape line rather than lift it. 

If you are using a Xacto knife to assist in un masking, gentle is the key word...lay the knife flat against the surface of the tape and gently slide the blade under the tape edge, then rotate up to lift.  This will prevent you from cutting into the underlying finish.

Most of all, don't get in a hurry, or you'll be revisiting parts of the process.

cheers,

rody

1 comment:

Colleen said...

Ah, that pink is awesome! Jealous :)