Thread: bc\cc under trunk and hood advice?

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Several... unless you are just trying to make it a shiney color with minimum work.

I am not a chemist, but here are my observations anyway.

Basecoat does not have to produce a gloss, so it does not have the 20-25% clear mixed in. As a result, it isn't as transparent, so it covers better.

You also don't need time for it to flow out to produce a gloss, and it is more porous and breathes better, so it drys faster.

If you are stacking coats to produce graphics, the edge is thinner.

As I was told years ago by a very experienced painter..."Basecoat always sticks to basecoat", so as you add basecoats or interim clear, you don't have to worry about the "time window", like you do on catalyzed paint. A lot of guys feel the need to sand basecoat after a long period, but I have never had one adhesion problem from this. (....and I use a very sticky masking tape!) I don't know if it's true for other brands, but I mix 3 brands of basecoat paint without any problems. (R-M, X-Otic, and HOK)

The topcoat clear has the job of offering the protection, so you don't have the expense of adding hardener to every coat... or being exposed to polyisocyanates on every coat.

Topcoat clear seems to sand and buff better, since it doesn't clog the paper up with pigment, and polishes up to a little higher gloss.

There may be more ....but if all you are doing is adding shiney color to jams or frames....

BTW, At the instruction of my R-M/HOK dealer... I make single stage by adding 20-25% clear to the base, then also include a higher percentage of hardener than what the clear alone demands. I've done it several times, and it seems to work fine.

Originally Posted by HOTRODPAINT

BTW, At the instruction of my R-M/HOK dealer... I make single stage by adding 20-25% clear to the base, then also include a higher percentage of hardener than what the clear alone demands. I've done it several times, and it seems to work fine.

Thanks for your reply - just the type of info I was looking for to understand basics, especially this last part on making single stage. One more question - for a hiboy frame where parts are fully exposed adjacent to the body ('33, so not as much exposed as a '32) it sounds like a good base coat + clear would be the best approach?

Originally Posted by rspears

Thanks for your reply - just the type of info I was looking for to understand basics, especially this last part on making single stage. One more question - for a hiboy frame where parts are fully exposed adjacent to the body ('33, so not as much exposed as a '32) it sounds like a good base coat + clear would be the best approach?

Roger, I just traveled the "same path" this week on my 32 High Boy. Let me give you some of my findings.

First, Jay (aka, Hot Rod Paint) gave me "dead nuts on" good advice. He told me I would not be satisfied using only single stage, and I should just bite the bullet and do the BC/CC system. It took, two quarts of sealer, one gallon of (waterborne) base, and almost two gallons of clear material to paint all 27 pieces (many were painted on all sides). That was a little over $1100. at a "discounted shop cost" in paint material. The paint job turned out beyond my best hope, it looks a mile deep.

Since I live in California, I had some serious reservations about using "the now required" waterborne base coat after spending almost one year of weekends doing body prep and fab in my driveway. Jay was not a big believer in the water paint, but I had no choice and it now looks great. Only time will tell how well it holds up.

Ken Thurm (wisely) suggested that I use a powdercoat applied primer on the body parts (in grey). I also powdercoated the frame and rear axle in semi black. It's much cheaper to do the powdercoat process when you take into consideration the cost of media blasting and purchasing epoxy primer material. Note, after the frame was coated, I taped it off and prepped and finished the outside showing areas in the same BC/CC as the body was done. In my opinion, as good as powdercoat is it still does not have the same finish as paint and even though I could color match it, I feel painting the outside of the frame will allow it to be repaired and touched up in the future from the rock chips. Jay, told me to just treat the powdercoat base as "epoxy primer" and finish accordingly.

In conclusion, the cost of materials was staggering to me, $850 for a gallon of dark red, and then they charged me $12 more FOR A GALLON OF WATER (lol). I spent almost $4K in materials to get it from rusted new steel...........to top coat. None of this was in labor, I did everything in my driveway, and only "hired out" the actual final spraying. I have a high respect for what custom painters do and the effort it takes them to turn out a glass smooth paint job.

Now as the instructions say, it time to SIMPLY REASSEMBLE! LOL

Being in the MidWest "Ice Belt" I have some serious reservations with powder coating anything that is going to have a chance of being exposed to the winter melt products used in this area. I have seen too many factory powder coated products end up hiding massive rust problems beneath their stiff film of "protection". From that respect I lean to painting the exposed surfaces. Based on what I am seeing, perhaps the right approach for me is to single stage the "unseen" parts of the frame, and to then proceed with BC/CC for the visible areas on the outside of the rails forward of the body line.

I am going to visit with a local powder coat guy in the near future to chat about his process, and how he believes it stands up to winter abuse. I do not know at this point how much winter time my ride will get, but I like to be prepared to say it is a 4 season vehicle, ready to go at any time.

Originally Posted by rspears

Being in the MidWest "Ice Belt" I have some serious reservations with powder coating anything that is going to have a chance of being exposed to the winter melt products used in this area. I have seen too many factory powder coated products end up hiding massive rust problems beneath their stiff film of "protection". From that respect I lean to painting the exposed surfaces. Based on what I am seeing, perhaps the right approach for me is to single stage the "unseen" parts of the frame, and to then proceed with BC/CC for the visible areas on the outside of the rails forward of the body line.

I am going to visit with a local powder coat guy in the near future to chat about his process, and how he believes it stands up to winter abuse. I do not know at this point how much winter time my ride will get, but I like to be prepared to say it is a 4 season vehicle, ready to go at any time.

The neat thing about a place like club hot rod is that we can talk it over. I would agree what works best in sunny So. Cal. might not be the best for your area. The thing that sold me was there was no way to get paint into every "nook and cranny" on my body, inside the doors, much less the frame. The electrostatic powdercoat process sucks the paint (plastic?) into places paint will never go. Also they did a phosphate treatment (like an acid wash) after it was media blasted to etch the metal before the powdercoat primer was applied.

The one thing to keep in mind when talking to your powdercoater is that just like in any kind of painting, it's all about THE PREP.