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MG MGB GT V8 Factory Originals Technical - Body prepping question
|OK, Iíve got the easy part done, the engine is out along with the interior. Now hereís where things go awry; Iíve got that waxoyl <spelling> on the bottom and boy is this stuff good. I figure itís been on since í77 and itís only now starting to peel off. I would like to take this off and apply POR 15 or some sort of Rhino liner, and I plan on (someday) painting a new/different color along with flared fenders (metal). Knowing that this is the future of things I hate to start stuffing components in just to UNDO everything when Iím ready to paint. Iím trying to locate a place to have my shell acid dipped in the Virginia/Maryland area. Iíve seen quite a few of you guys (on this BBS) in the area and wonder if you can help me?|
|I think the general mg bbs had a topic about acid dipping a few weeks ago. The general conclusion (as I saw it) was that it's difficult to stop the etching process, and get it out of all the small cracks. Personally, I media blasted my car down to bare steel, and had it epoxy coated afterwards. Only took about 2 days, cost me $1100, and left me with a car I could do anything to I wanted. (And trust me I did)|
I heard similar reports about acid dipping. What type of media did they use on yours. I used to have a 58 pickup that was sand blasted and everytime I got on the highway I ended up with sand everywhere (just like I spent a day at the beach). Did you have to remove everything (rubber, etc...) for the blasting? I'm new at this prep work, what's this epoxy coating, different from primer, same?
|Aluminum oxide is the media commonly used. It's not nearly as destructive as sand is. Anything you don't remove from the car will probably be destroyed. I had my car stripped down to 2 axles and a steering wheel. 100% of everything else was removed. I worked for a long time to get all the media out, and eventually I got out my leaf blower, and covered myself up real good and started working my way through the car. About an hour later I was done and all the media was out of the cracks and crevices. No problems since, and that was just over 2 years ago. Epoxy primer by ppg was used on the car immediately after it was media blasted (kept the car from rusting). The results were just amazing.|
|On my V6 project I had the 75 shell I have blasted with baking soda. The interior, underside and engine bay were sand blasted but the doors, fenders, trunk were all given the soda treatment and everything was epoxy primed. I have the car on my home made rotisserie which in all the rolling over seems to have gotten out most of the residual media.|
There is nothing like starting with a clean, freshly primed shell and it cost $1100,00 which saved me probably several hundred hours of work.
Since doing this I have replaced the floors, rockers, grafted on another right rear quarter, and flared the fenders 3 inches using foam and fiberglass.
Next we reinforce the rear spring hangers and tie them to the center cross member, box them and mount traction and panhard bars to the Dana 44 rear end. I might actually then begin to paint this monster!
That rotisserie sounds great! Do you have drawnings that you can send,where are the attaching points? I would imagine the bumper mounts but I have no idea of the weight of an empty shell.
Justin, Tom, Did you guys Epoxy prime yourselves, or have it done?
|Thomas: Can't help but ask about your fender flares made with "foam and fiberglass". I would like to flare my fenders as well but don't have a good plan on how to do it. If you could describe more I would appreciate it. Pic's would be nice if you have any.|
|The epoxy was put on by the media blasting shop, and a lot of it actually got sanded off during more body prep procedures, so it was really nothing more then a stop gap measure for rust. Those body rotisserie's are cool things! I think Skye has plans for them on his website: http://mgbexperience.com I didn't use one, but easily could have, and probably should have. Oh well, such is life!|
"Foam and Fiberglass" is a method I use a lot of when designing door panels, kick panels, or dashboard for cars. You use something like surfboard foam and sand and form it to the desired shape. Then when you lay fiberglass on it, it becomes that shape. Sounds easy, till you try and start forming a perfect arch by hand with a rasp and a DA sander. That's where the artistry takes shape.
Now if someone saved their foam shapes, and made molds out of them (and they were good, clean molds) they could pretty easily sell me a set of flares to help offset their time expense into the project. ;)
|Media blasting has the same issues you are sighting about ecid dipping, the media gets into cracks and crevasses and only comes out when you are painting or afterward.. Everyont I talked to says go "soda blasting" route instead. The media used is water soluble, os after then blast it they rinse or dip the item (chassis) with water to disolve the media..|
I like the foam mold idea too!!
|I have to disagree a *little* bit Larry. I had all the media out of my car long before the paint man got it. I haven't had any media show up in the two years since I did the project. That leaf blower cleaned it all right out. It's possible the baking soda might still be better, but I'm just saying you can get all the media out w/o any major problems.|
Foam molding is a cool way to make stuff as long as the mold is good. Just like any car part, it's only as perfect as the mold, or press used to make it.
|yeah you went over the top with the leaf blower HEH!! I am just relaying info I heard form locals aboutit.. They were getting a bit beyond pissed when trying to prep the car as just as they would reach for the primer, more sand would appear heh..|
|I used the expandable foam you buy in cans at home depot and isocyanate foam sheets they sell as outer sheathing for construction. Don't use stryofoam, it melts!|
I may think about pulling some molds off these fenders when they are done but that's still a ways off.
I had the body shop that did the soda blasting put on the primer and just like Justin I have sanded a lot off in doing the other body work but it is still on about 70% of the body.
Don't even think about applying any 2 part paint yourself unless you have an outside air supply! The fumes can and will mess you up big time if all you are using is activated charcoal respirators. They do not stop the isocyanate fumes.
My rotisserie is made of 2x10 lumber with a 4x4 stanchion at each end. The car is mounted by bolting 2x6's thru the bumper mounts and using a 1 inch pipe and floor flange to act as the axle. The whole deal is on big casters to move it around.
|Check out http://www.accessiblesystems.com/|
That link has some interesting parts. I liked the Easy Tilter and the Universal Body Brace. The body brace would be great for replacing sills/rockers. With the turn-buckles you could rack the frame until it was straight and keep it there until the new sills were in place.
|Ah, Jim, yes! Another tool we must all have in our little shops. :-)|
This thread was discussed between 31/07/2003 and 07/08/2003
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