Author Topic: Undercarriage Cleaning and Refinishing Suggestions Needed  (Read 12544 times)

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Offline 10thAnniversarySearch

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Undercarriage Cleaning and Refinishing Suggestions Needed
« on: July 13, 2012, 05:23:50 PM »
Gotta start my restoration with the undercarriage.  Won't be a frame off process.  Plan on a NICE infrequent driver, not a show car.

I've been trying to decide on sand blasting,  soda blasting or wire wheel/drill cleaning of undercarriage.  So far I've been warned that sand will be found for years to come, soda is even worse AND holds moisture.  The wire wheel sounds long and tedious. 

Today, someone told me about glass beads, which will polish as well as strip.  And then a method using dry ice!  Anyone heard o experimented with this?  Sounds expensive, BUT, it can be done anywhere (including outside) as there is no media left.

Finally, anyone have any thoughts on finishing the underside with Line X material?  Similar material is being used in new car manufacturing.  Sounds good at first, durable, hides some flaws, comes in rattle cans.  Thoughts?

Offline Grand73Am

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #1 on: July 16, 2012, 07:09:39 PM »
To what extent will you be disassembling the car? Will you be removing the engine, trans and rearend? If you're going to clean up the frame and underbody, it'll be hard with them in the way.
I'd sandblast, and whatever you don't want to get sand on should be covered with plastic sheeting attached with duct tape. So, if you're leaving the drivetrain in, mask them off really well. Cover the rest of the car too. Then, jack the car up as high as you can and support with a bunch of jack stands. I'd also lay some plastic sheeting on the ground and then slide under there and start blasting. The plastic on the ground will be more comfy for you and catch a lot of the sand to make cleanup easier afterwards. You can successfully blow out the sand afterwards to the point where it won't be falling out later. Use an air blower nozzle with an extension on it that you can slide a rubber hose on it to reach into hard to reach places to blow out. Once you get the car ready to blast, the actual blasting shouldn't take very long and the results will be cleaner than any other way. I guess you have a 79, so after the cleanup, I'd spray the bottom with PPG's black epoxy primer, since the bottom of a 79 was black. Then I'd spray it with some semi-gloss black single stage urethane paint. That's using a spray gun. I guess you have a compressor if you've considered blasting, so no reason not to use a spray gun. It would look more like a quality resto that way, being clean and detailed looking, which adds value to your car. An undercoating product is not as desirable, value-wise.
No reason to use glass beads. They are much more expensive than sand. And you don't need a polishing action. Paint doesn't stick as well to a smooth surface. The Black Diamond fine sand(30-60) would be my choice. Dupont Starblast sand is great too, but costs twice as much.
I'm not sure what you do about the front suspension, since it's better to do it without those parts installed too. The greaseable parts, like ball joints and tie rod ends should be protected. If you're not doing the frame, then cover the front suspension area to keep sand from it. If you want to do the frame, you could blast just the bottom of the body, and wire brush the frame to keep sand out of the suspension and steering area.
Wire brushing with a cup brush on a drill would be my second choice. Tedious, yes, but there's no easy way, if you're doing it yourself.
Is that dry ice blasting? I wonder why it has to be dry ice and not wet ice :) . Sounds good if it works, and shouldn't hurt other parts of the car, and somebody else does it. Hard part is paying for it, I suppose  :) .
Steve F.

Offline 10thAnniversarySearch

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #2 on: July 16, 2012, 08:04:11 PM »
Thanks for the reply Grand73Am.  The dry Ice sounded neat, but VERY expensive I'm sure.  (I guess the wet ice would foul up the equipment.)   I've went with the wire brushes and drill (Pac Man Style) .  Not too bad so far.  Much better than I had thought.

Offline Grand73Am

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #3 on: July 16, 2012, 09:15:53 PM »
You're welcome. Good to know which way you went. Not a pleasant job, but at least a TA isn't really a very big car. Imagine having to do a full size car :) .
Steve F.

Offline 80Formula

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #4 on: July 21, 2012, 09:41:29 AM »
I just recently did mine with the wire wheel method and it turned out great, but was an absoutly nightmare to do. I've been working on cars for years and I would say it's the most tedious work I've ever done, and took over two months to do,..

The mediablasting method is much faster, but media will go everywhere. If you don't have a rotisserie and/or can't do it outside, it might not be the most advisable route.

Offline 10thAnniversarySearch

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #5 on: August 01, 2012, 10:01:35 AM »
I just recently did mine with the wire wheel method and it turned out great, but was an absoutly nightmare to do. I've been working on cars for years and I would say it's the most tedious work I've ever done, and took over two months to do,..

Thanks for the insight.  I've been doing the wire brush route with the car up on jack stands.  It's going pretty well all the loose "flakey" rust is gone now from the rear edge of the rear floor pans to the rear valance.  (the rear valance will probably have to be replaced)  Some spots are difficult to get to, like between the frame and the edge of the trunk floor.  Gas tank, exhaust, etc., has all been removed.  I think it's close to paint time for this section.  What's best to use to clean and prep the area for paint?  (POR 15) 

Offline 81Turbo TA

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #6 on: August 11, 2012, 09:40:18 PM »
did you see  greenbirds  car?    I believe he didnt use any sandblasting at all/

Offline Greenbird76

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #7 on: August 12, 2012, 11:04:19 AM »
did you see  greenbirds  car?    I believe he didnt use any sandblasting at all/
yup.  None what so ever.  Just sweat, some blood and some tears after the blood.  All sizes and types of brushes angle grinders and drills too.  I did so a lot of sheet metal replacement too.  Check out my complete build page for more pics and of the resto-  http://www.allgentransams.com/TATA/index.php?topic=2327.0
Before

after





Offline 81Turbo TA

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #8 on: August 12, 2012, 02:59:46 PM »
yeah,,,I need to do the same, but its just too hot and I'm not motivated at all to get under there. I keep saying  ''in the fall''.  There is just so much different work my car needs that I really dont know where to start first.

Offline Greenbird76

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #9 on: August 13, 2012, 12:38:30 AM »
That's where I was when I started my car.  I actually knew about all the bountiful rust in the rear before I started tearing into her.  I would sit under the car for hours working out my plan of attack.  At the same time I was tearing my old project, a 1980 Formy into pieces.  Stripped her to nothing and salvaged anything I could.  I even scavenged her rear frame rails.  It gave me a heads up of what would be needed for the 76.  Work wise that is.  My small shop is what motivated me.  In the past I would be on my back in a gravel drive way working on cars.  Now with my shop, I can work on them year round!

Offline 10thAnniversarySearch

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #10 on: August 13, 2012, 09:37:04 AM »
VERY impressive.  Mine is coming along, but no comparison to Greenbid's.

before...


during...


so far...

Offline Greenbird76

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #11 on: August 13, 2012, 10:26:18 AM »
That looks good.   8)   Just keep on plucking away at it.  My build started small and then as I went along, I just wanted everything refurbished to new and I am was not concerned about keeping the car stock underneath or in the engine bay.  Only the exterior and interior will remain stock.  I was working on a tight budget so I would research all parts quite deeply before buying them. 
I really would consider removing the rear diff and springs.  I found it much easier to bench restore all sway bars and mounting hardware.  Also replacing all suspension bushings would be great also.  It took me one day to completely strip and SEM rust mort my rear end.  Another day of painting it with rusty metal primer, engine paint and engine clear.  The rear I used was a rebuilt 410 posi out of a 81 camaro.  Non original gears of course!
« Last Edit: August 13, 2012, 10:29:35 AM by Greenbird76 »

Offline 10thAnniversarySearch

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #12 on: August 13, 2012, 01:41:02 PM »
I was working on a tight budget so I would research all parts quite deeply before buying them.   

Thanks for the compliment.  That's exactly what I'm doing now with fuel lines.  I have the tank ready to install but haven't picked the "best" source for new lines yet. 

My primary concerns are safe, dependable, looks good.  In that order. 

I'm not sure about moving the rear end for now.  I have it pretty much ready to go, most of the rust has been removed.  Degreased and pepped for the POR 15.  Need to remove brakes lines, clips, and stainless tag.

Offline 80Formula

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #13 on: August 17, 2012, 08:47:47 AM »
I just recently did mine with the wire wheel method and it turned out great, but was an absoutly nightmare to do. I've been working on cars for years and I would say it's the most tedious work I've ever done, and took over two months to do,..

Thanks for the insight.  I've been doing the wire brush route with the car up on jack stands.  It's going pretty well all the loose "flakey" rust is gone now from the rear edge of the rear floor pans to the rear valance.  (the rear valance will probably have to be replaced)  Some spots are difficult to get to, like between the frame and the edge of the trunk floor.  Gas tank, exhaust, etc., has all been removed.  I think it's close to paint time for this section.  What's best to use to clean and prep the area for paint?  (POR 15) 

For that I used a die grinder with a 1" knotted brush on the end to at. For the really tight areas that good ol' hand brush does the trick.

Once I got everything down to bare metal, it just hit everything over once more with some degreaser, then some of eastwoods "pre" spray, then hit it with paint.

Offline Greenbird76

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Re: Undercarriage Cleaning and Refinishing Suggestions Needed
« Reply #14 on: August 17, 2012, 11:28:20 AM »
I was working on a tight budget so I would research all parts quite deeply before buying them.   

Thanks for the compliment.  That's exactly what I'm doing now with fuel lines.  I have the tank ready to install but haven't picked the "best" source for new lines yet. 

My primary concerns are safe, dependable, looks good.  In that order. 

I'm not sure about moving the rear end for now.  I have it pretty much ready to go, most of the rust has been removed.  Degreased and pepped for the POR 15.  Need to remove brakes lines, clips, and stainless tag.
I also used a small pnuematic angle grinder that accepts abrassive discs.  That allowed me to get in very tight areas.   For cleaning I would use a good degreaser.  I used some simple green, then some high flash solvent like thinner or even brake cleaner to dissolve the grease.  I also used paint stripper to get everything to bare metal on a ll my donor panels from my parts cars.  I did not replace my line clips either.  I simply wire wheeled them with a bench grinder and sprayed them with Rustoleum clear.  I actually did this to every piece of hardware and bolt I reused.  That stuff is tough and adheres to anything clean and rust free.   For areas that did not have any rust and the original paint was in good shape, I scuffed it up with some scotch brite and painted over it.