Refinishing the LT5 top end, info needed.

[bdw18_123]

Got a couple questions, couldn't find much of any info on this in "Solutions" or with a forum search.

1. Is it ok to beadblast the top end parts (plenum, cam covers, etc.) to get the old paint off before painting or powder-coating? Or is it better to chemically strip them?

2. Can anyone give any details as to the process for making the plenum smoother for painting/powder-coating? Sandpaper grits to use, etc?

3. Does anyone have any insight into painting vs. powder-coating the LT5's top end? Which is better? Or is it just a preference/whichever is easier type thing? I have heard that powder-coating could possibly degrade/turn yellowish with time?

[HAWAIIZR-1]

Got a couple questions, couldn't find much of any info on this in "Solutions" or with a forum search.

1. Is it ok to beadblast the top end parts (plenum, cam covers, etc.) to get the old paint off before painting or powder-coating? Or is it better to chemically strip them?

2. Can anyone give any details as to the process for making the plenum smoother for painting/powder-coating? Sandpaper grits to use, etc?

3. Does anyone have any insight into painting vs. powder-coating the LT5's top end? Which is better? Or is it just a preference/whichever is easier type thing? I have heard that powder-coating could possibly degrade/turn yellowish with time?

Sorry, I don't know all the details as I did not do mine myself but here is what I know from the company.

1. The shop that I used for powder coating bead blasted all my parts first then the baked them (I forgot what temperature to remove impurities in the metal). Then they used a primer powder coat and then powder coated color with a clear powder coat.

3. I went for powder coating for the durability. I have never heard about the powder coating changing color and I hope it does not happen to mine in the long term.

I just don't have the talent or equipment to attempt it myself so I sent it out to a powder coating shop to do.. Hopefully someone that had done it themselves will chime in and just wanted to share my powder coating work done.

These are the local folks I used but they have some good info about the process, etc. I think it was about $500 to do the cam covers, plenum, IHs, TB, air horn. I paid $75 per wheel to do my stock wheels to black centers and now $75 per center for the CCWs. Not cheap, but very high quality and I think it will last a long time with low maintenance.

http://www.sunsetpowdercoating.com/products-services.html

[Paul Workman]

Marc H no longer powder coats because "PC tends to be brittle and it will often crack and slough off around the bolts." He paints his.

I painted mine. I simply wet sanded mine down then used a filler primer and more sanding to level and smooth before applying the finish coats: a high-temp silver wheel paint and high temp clear coats. It doesn't crack, apparently.

As for yellowing, Marc had problems with some powder coats that did turn yellow (more golden - almost looks like it was on purpose!). However, there are high-temp clear powder coats available where that shouldn't be a problem.

The wheel paint really contrasts with the old faded green-grey of my stock 90 in this photo - to give you an I-dear.

http://i185.photobucket.com/albums/x220/6PPC_bucket/Vettes/PlenumLarge-1.jpg

An unusual shot...

http://i185.photobucket.com/albums/x220/6PPC_bucket/Vettes/LT5andme006Large.jpg

Another look at the color...

http://i185.photobucket.com/albums/x220/6PPC_bucket/Vettes/camcoverpaint003Large.jpg

Then you could always just polish it like Keith Moudy did...

http://i185.photobucket.com/albums/x220/6PPC_bucket/Vettes/KeithsLT5-1-1.jpg

Lotza options!

P.

[John Boothby]

Man, that polished engine looks sweet!

[rhipsher]

Your not supposed to use a two part powder coat with clear coat otherwise the clear coat will turn yellow over time from engine heat. Thats why it pays to take it to somebody who specializes in powder coating show cars ect. They already know what works and what doesn't work and how to properly prep everything.
Since I had mine PC'ed I've had to take the plenum off to replace an alternator and another time to replace a starter. There was no cracking or flaking off around any of the holes. If you want the best most indistructable finish possible for your pride and joy powder coating is the only way to go. I just don't know why anyone would go through all the painstaking process of removing all the top end stuff prep prime and paint it when it's going to only last 4-5 years before it starts flaking off. Even Sanjay had to take his 415 to Coreys and have the whole top end re finished because the LPE paint started flaking off. "I'm just saying!":dontknow:

John is the freakin man at Precision Powder Coating. http://precisionpowder.net/

[-=Jeff=-]

Got a couple questions, couldn't find much of any info on this in "Solutions" or with a forum search.

2. Can anyone give any details as to the process for making the plenum smoother for painting/powder-coating? Sandpaper grits to use, etc?


start rougher 120 grit and work your way to 600 grit. that is what we did on my plenum.. most everything else was smoother.

what we did not sand on the plenum was the recess in the center on the top and looking at it you can tell. We also kept going on the top to polish it

you can see the texture difference best in this picture

http://www.vettextc.net/jeff/LT5/IMG_1326_1.jpg

http://www.vettextc.net/jeff/LT5/RED-LT5.jpg

[rudolph schenker]

Marc H. did mine and I'm very pleased with it!


http://img.photobucket.com/albums/v737/rschenker/LT%205/104_1455.jpg

http://img.photobucket.com/albums/v737/rschenker/LT%205/104_1458.jpg

[bdw18_123]

Thanks for the info guys! Very nice looking LT5's!

We will probably be painting the LT5 in Evan's '92 Z and I'll most likely do the same on mine. We are planning to go with metallic silver with black letters and red numbers.

[rogerzr1]

Marc H. did mine and I'm very pleased with it!


http://img.photobucket.com/albums/v737/rschenker/LT%205/104_1455.jpg

http://img.photobucket.com/albums/v737/rschenker/LT%205/104_1458.jpg

WOW, that looks great. That is what I want to do to mine. What typr of paint and what color did Marc use?

[Locobob]

How often does powder coating result in cracking or scaling of powder coat around or beneath bolt heads? How do you prevent cracking of the powder coat when tightening bolts?

Does this problem exist when using washers?
Would using Jerry's new dowty washers help? http://www.zr1.net/forum/showthread.php?t=4696

I have never seen powder crack under a bolt. I have seen bolts loose torque because of powder - which is why I scuffed up you cam cover bolt surfaces.

[tomtom72]

I used the rattle cans from LPE, but Duplicolor has the same stuff cheaper. I painted my plenum & I/H's back in October 05 and the stuff hasn't faded, cracked, flaked or done any thing unwanted. The plenum has been off a coupla times since also, and no flaking at the bolt holes either.

I used a low VOC aircraft paint remover, for use on thin aluminum so I guess it's not too caustic? Any way, scotch bright pads & small brass bristle brushes to help the remover, a wash down & dry and then a high heat primer & then the paint. Just don't make the mistake I made with the clear top coat....wait a few days for the color coat to dry. I was pressed for time and only waited about 10 hours....bad decision!:o
JMHO
:cheers:
Tom

[tomtom72]

Actually no....it didn't wrinkle....It changed color. It went from LPE silver/gray to a gray/with a green highlight...or at least that's what it lookes like to me....I was a bit peeved to say the least.:censored: