[stonedchihuahua]

Okay I have a fair bit of surface rust under my car and the undercoating is pretty thick and hard to sand through.. so could I sand blast the underside of my car without having to rip it all apart... it is an 85 camaro by the way... will I need to cover the fuel/brake lines? I know of someone who has a sandblaster so would this be the best option? What other options are there?

 

[Halloweenking]

Its a fine option, but definatly remove all fuel and brake lines and fuel tank. you will also have a bad time unless you have a rotisserie to put the body on. High speed sand or blasting media bouncing off the sheetmetal at close range is not only dangerous and can get quite nasty, but also very messy. Just sand off all you can, get some Por-15 metal ready, coat the surface and spray or paint a coat or two of por-15, you'll never see rust again and the bottom of you car will be smooth and clean and vertually scratch and chiproof. Have fun with the blaster if you go that route, and definatly wear thick clothing and gloves and face protection if you like your skin.

HK

 

[stonedchihuahua]

umm I am not sure how well the sandblasting is gunna work though.. I doubt I will be able to remove all the fuel and brake lines... and the fuel thank... I did some sanding and to do a 2 inch by 2 inch area it took 10 minutes!!!!! I mean what the hell it will take weeks!!!

 

[Halloweenking]

well if you want quality you have to be willing to put the time and elbow grease in. I know it sucks, but its what you have to do. If you are going to do blasting you must take off all of the rubber lines (brake) and cover up the others to make sure you don't puncture or wear away something that could turn into a real problem. If the blasting you tried wasn't cutting it maby your not using the right media for the job. Also you must remove the fuel tank because media blasting causes the surface to get quite warm, and depending on the type of media you use could cause sparks or even the overheating and warping of the sheetmetal/metal. Por-15 also has a good quality stripper you could try instead of trying to blast or sand the undercoating off. After the coating off just prep the surface rust as I stated before and coat

By the way, this is my third week on my underside of my T/A, granted I had more to do (floorboards) and a few rain days, but I'm still not done and ready for the por-15 yet. Still have alot of 20+yr old grime to clean and surface rust to prep. Oh the funnest part of the restoration <img src="graemlins/spank.gif" border="0" alt="[spank]" /> <img src="graemlins/pain.gif" border="0" alt="[pain]" />

HK

 

[stonedchihuahua]

yeah but thing about this is... I have heat shield in front of the fuel tank... there is nothing that needs to be blasted very close to the fuel tank... the engine area could use a good blast so should i pull the engine or just cover everything... also my brake and fuel lines where all the blasting needs to be done are the metal ones... so is this a good idea or bad... what would work good to cover them...???/ I might have to remove all this stuff but I just wouldn't know how to put it all back together... maybe this is something I should do when I swap my diff... although I wanna do it before I get the thing painted so I don't screw up my paint...

 

[Halloweenking]

Well it all depends on how you want your car to turn out. by pulling the engine and tank and other things you'll coat all of the bottom of the car and not have to worry about rust and it will look very nice. If you don't pull anything and just do certain parts, it will look very odd and basically ugly with fresh clean paint next to rusted dirty grimey things, that why I say if your going to all the trouble of doing a little peice just save yourself the anguish of working around things and take it off and get a very nice looking underbody appearance that would look great with you new paint. You can cover them with thick grey duct tape and it will sheild them from the blast. covering the stuff in the engine compartment is fine as well, but its just easier to get it out of the way and go one step further. The best thing to do when disasembling a car is to either draw diagrams or take pictures and lable each peice or if it bolts put them in labled ziplock bags. This is exspecially good with shims or rubber peices that will change things if they aren't put back in the exact same place. Either way will work, but since your already under there and you plan to put money ito it as well as much work, you nmight as well go a little bit further and have that much better of a car.

HK

 

[stonedchihuahua]

yeah... will the sandblasting damage my suspension and stuff??? cuz I want to find some nice canned paints and spray my coils and drums adn such but the thing is I need to clean them up first... I think the rear axel is gunna be swapped with a 9 inch so I don't care too much about that... do you think it would be bad if I saved doing the engine compartment for when I do my engine swap to save me some energy?

 

[4 Jaw Chuck]

You need to decide if you want to do a frame off restoration or pressure wash and seal with new undercoat. Lazy mans way is to steam pressure wash and undercoat.

 

[crshrmn3]

You'll be surprised just where all that sand will get into and how far it will travel. That stuff will crawl into the tightest of spots. I was sand blasting a coal crusher in the parking lot of a shop once. This was with a big industrial type sand blaster. We ended up getting complaints from people who lived down the road from the shop. We went over to see what they were complaining about, the bottom of their swimming pool had a nice black sand bottom. Needless to say, the boss had us stop blasting in the parking lot.

 

[Kevin45]

Sandblasting will not hurt the brake lines, it will prematurely wear out the rubber lines, it will get into every nook and cranny, it will be a real mess to do laying on your back, it will not remove any undercoating that you may have, it will embed the sand into the undercoating you may have. If possible get it up on a lift and use and use a wire brush by hand, a wire brush on a drill, a putty knife, and a power washer to get it as clean as possible. Then get some POR-15 and paint the underneath. The only other way is a frame off job and I really don't think you want to get into that. One other thing you may want to look into...A couple of guys told me about it that went to the Cars & Parts swap meet...is this contraption that bolts to your hubs and is like a huge loop. You take off the tires, bolt this contraption to the hubs, drain the oil, gas, tranny fluid, and radiator and you can roll the car upside down. It is different than a rotisserie. If I can find it on the net I'll let you know. Weimer knows what I'm talking about because he's seen it and maybe when he gets on here he'll remember the name.

Kevin

 

[crshrmn3]

I recall seeing an article where someone got 3 steel wheels. Cut one in half and welded the halves to the outside of two other steel wheels. Then bolt these fabricated steel wheels on one side of the car. They then took 2 more steel wheels and welded lifting eyes to the wheels and bolted these wheels on the oppisite side of the car. Being in a garage, they were able to lift the one side of the car and using the fabricated wheels as the pivot point. They were able to rotate the car almost 90 degree to work on the bottom. Now, I don't know if that would be a recommended method, or what it would do to the suspension on either side. Just an idea.

"Poor guys have poor ways." lol

 

[stonedchihuahua]

umm okay so since this way isn't gunna work too well... (my car is unibody.. it is going to get sand everywhere) would I be better off using a grinder??? oh yeah and about the sand blasing not removing undercoating... there is surface rust under most of it so when I touch it in some areas it falls off... these are the areas that need cleaning up the most

 

[Kevin45]

Too many differences in metal to use a big grinder. Small 3" grinder maybe, a putty knife and a lot of elbow grease. Sorry, no simple ways, no magic wand. Sometimes you just gotta suck it up and realize what you want and what it going to actually be are two different things. I went the easy route to clean the underneath of mine. Had the whole car dip stripped and still it took 5 times in the tank and a guy with a putty knife on his back to get the undercoating off.

Kevin

 

[stonedchihuahua]

yes... well what about a wire brush on a grinder??/ they take stuff off quickly?