Another Painting Question

[Crossrodes]

My paint supplier recommended that I use USC Bumper and Cladding Coat Adhesion Primer on the plastic parts.  I have done this.  My question is had anyone sanded this stuff and then sprayed hi-build primer on top of this so that you can sand to a nice finish?

[montmil]

Not familiar with the USC product but do understand the thought behind it. I belive the product you're using or considering is designed for the slightly flexible plastic bumper covers found on most cars these days.

The BMW side covers are a resin-cast material that will accept most any primer you may choose to use. Yes, most all are sandable save the surfacer-sealer products that are often used to produce a consistent color base after applications of filler, primer, blocking primer, blah blah blah...

Personally, I'd take a pass on the product. I've painted a couple pairs of side panels and if you 'bonk' something hard enough to seriously flex the panel, you'll have more to worry about that the paint.

Monte

[nhmaf]

Well, the front fender might benefit from a more flexible primer - as it is more flexible (and usually struck by lots of little stones, etc) than the sidecovers.  But, how many different paints does one want to have for (1) project ?   I think you may be OK with the regular stuff if you don't want to spend more $$ for something that you won't use so much of..

[Justin B.]

I just sand and apply the proper primer for the paint system I'm using.  It's not rocket science if you just go to the paint distributor and specify what you want to do and they will select the primer, reducers, base-coats, etc. for you and guarantee they will be compatible.  Nothing more aggravating than getting all of the prep perfect only to have the base-coat or clear-coat react with some spray-bomb crap two or three layers down and turn out looking like 'gator hide!

If you insist on spray-cans then check out NAPA as they used to sell regular automotive quality paint in spray cans, and probably still do.

The materials(two base-coats with their reducers, Candy Red dye, two different clears with activators/reducers) to replicate a BMW Smoke Red paint job are in the $400 - $500 range as of a couple years ago but is enough for 2-3 bikes.  That doesn't count the primers and sealers which will add another $100...

With all the above you can get this:

[Mike V]

Damn Justin,

Very nice!  Did you apply the striping? Freehand and brush?  Masked?

[Crossrodes]

Justin that is very nice work.  The scheme is similar to the scheme I had originally on my R65 but it was showing its age.  I spoke with the paint supplier and he told me to go ahead and apply the high build primer to the bumper cladding which he also recommended.  The paint I am using is automotive paint and is mixed when I order it and put into the spray cans.  I don't insist on spray cans but I don't have a paint facility to do otherwise.  A friend painted his this way and it turned out beautifully so I'm giving it a shot too.

I ran out of clear coat and my supplier will not have more in until next Monday so I checked with NAPA but they don't have the 2 part that I want (protects the tank against gasoline spills).  So NAPA is out.

[Justin B.]

Cool.  As long as you adhere to your paint supplier's recommendations you should be OK.  The only thing I question is a special adhesion promoter for the side panels and front fender.

[Barry]

I ran out of clear coat and my supplier will not have more in until next Monday so I checked with NAPA but they don't have the 2 part that I want (protects the tank against gasoline spills).

Is this the new type of 2 pack in a spray can where the hardener is released by a button inside the can ?

There seems to be one or two different makes of this now. It will be interesting to hear which you are using and how the finish turns out.

If it works well it might be the key to getting a decently durable finish from a spray can.

[Crossrodes]

Barry, yes the hardener is released when you hit the button at the bottom of the can.  You have to shake the can both before and after hitting the button.  This particular product is called Spray Max.  It ain't cheap though.  Here in Canada it costs $32 per can.

In terms of how the finish turns out I first did the front fender and had lots of orange peel.  Next I did the side and back panels and they turned out really well.  The gas tank turned out well as far as I got before running out of clear coat.

After I had the orange peel effect on the front fender I spoke with the supplier about the orange peel and he told me that with this clear coat you really have to soak it on, which is what I did for the other pieces and it turned out well.

I've sanded the orange peel down smooth on the front fender and will re-do it when I get my new can of clear coat.

I thought by using 2000 grit sandpaper when sanding the orange peel I would get a good finish but I did not.  It was a dull finish.  In reading tips on the Internet I may not have waited long enough before I sanded it.  I waited 2 days after the clear-coat had been drying at about 21 C (72 F).  From what I read one person recommended waiting a week before sanding.  

Because of the length of time I will be waiting to re-spray the gas tank I will have to sand that also.  It will be about a week before I respray so I'll sand it with 2000 first to see what kind of finish I get after it has dried that long.

One thing I am really pleased with are the pin stripes I painted.  After getting the parts prepped I sprayed several coats of gold paint in the areas where the pin stripes would be.  After waiting overnight for the gold to set up, I applied 1/8" masking tape where the pinstripes would be.  I then wet sanded the gold that was left exposed with 600 grit being careful not to sand the masking tape and then starting spraying coats of red to the rest of the pieces.  After I had enough coverage of red (I think about 4 or 5 coats with the spray cans) I removed the masking tape and started applying the clear coat.

When the project is finished I'll post some pictures.

[Mike V]

Mike,

Curious about the striping; did you remove the masking before the paint cured and set, to allow for subtle flow at the masking edges or is this not necessary?  Did you end up with smooth edges at the mask edges?

You guys have more talent and gutts than I, "real" painting has always been a no-fly zone for me.  Great informative thread here.  At some point down the line the 78 R100/7 with red metal flake paint & gold stripes will need to be redone.

[Barry]

Mike,

If the finish is smooth I don't think the dull finish after 2000 grit sanding will matter if you are putting on more clear coat.  In the normal clear of base system the base coats are matt before the clear goes on.  

Spraymax doesn't seem to be available in the UK.  There are several others though at various prices. Expensive stuff but if it's tough and petrol resistant still good value compared to a expensive pro job.

[Crossrodes]

Mike V, my concern re the pin-striping was actually peeling the paint off when I removed the masking tape.  So I elected to wait overnight for the paint to set up sufficiently before applying the masking tape.  I think I waited about 12 hours.  One concern I had was that once I had the pinstripes unmasked probably about 13 hours had passed since I painted the gold.  I didn't want to sand the pinstripes as I would spoil the finish but I wasn't sure if the clear-coat would adhere properly to the pinstripes after this much dry time.  But I went ahead with the clear coat any way.  So far it seems to have worked...only time will tell if I have adhesion problems.  

I went over the masking tape and pressed it on very firmly after I first applied it so that I wouldn't have any paint bleeding past the edge of the masking tape.  The edges came out very nicely defined.  One thing to note is that I used automotive quality masking tape for this.  I don't think you'd get clear edges with any tape you bought from a place like Home Depot for house painting.

Barry, what I was attempting to accomplish with the 2000 grit sanding was a shiny finish.  I have seen this done on TV shows( and have done it on gelcoat on a boat with nice results).  I know that I will have a shiny finish when I clear-coat it again but If I have more orange peel I will want to smooth it out.  That is why I will wait the week for the clear-coat on the gas tank to set up and try the 2000 grit again to see if it will finish nicely.  Another option is to try a mild rubbing compound on the clear coat to see if I can get the shine back after the 2000 grit.  

My problem is that I don't have good painting facilities to do the job.  I paint outside in my back yard because of the fumes (very toxic and explosive) and immediately move the painted item indoors to dry.  Being outdoors I am exposed to low temperatures, wind and sometimes dust or other things in the air at this time of the year.  I'm going to have to pick the best conditions when I do the next coat.  I think the wind and low temperature may have contributed to the orange peel on the fender.    

[Justin B.]

Mike,

The pin-striping on the R100 tank was done by first spraying gold base then applying 3M tape, spray top color coats, wait 30 minutes, peel off tape, and fog the clear to it!  I put the clear extra heavy over the stripes that way it can be sanded down smooth...

Wait until the next day and wet-sand and buff...

[Crossrodes]

Justin sounds like you basically did the same as I did except for the sanding I did after I put the masking tape on the gold.  

One question....do you use any compound or other product when you do the buffing?

[Justin B.]

I use a product called "Clean-Cut" but your super fine grade 3M compounds are very good although pricey.  Use what your paint distributor recommends.  Several years ago I was buying compound and I brought the 3M stuff to the counter and the dude talked me into trying the other and I've used it ever since.  It costs about the same for a gallon as the 3M was for a quart!

It usually isn't good to sand between base and clear as most bases should be cleared in 30 minutes or so for proper adhesion.  The label on the paint can should have flash times, time between coats, etc.  Adhere to them...