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-   -   Best way to strip paint and rust from frame (http://www.airforums.com/forums/f44/best-way-to-strip-paint-and-rust-from-frame-195723.html)

JoleneAS 05-16-2019 10:37 AM

Best way to strip paint and rust from frame
 
Hey guys. Got a 1976 Overlander that I plan to give an entire week of attention to starting in a few days. The whole trailer is gutter to the subfloor. I have a few questions about restoring the frame:

1) What is the best way to strip paint and rust from the frame? I've read about people using wire wheels / wire cups, but I've also heard that this leaves a ton of wire particles everywhere. I'm doing this on my driveway and want to minimize the risk one of my kiddos gets a metal splinter, but if this is the best way to go, I'll do it.

2) I read about people having sagging outriggers requiring repair / replacement. What is the risk of keeping sagging outriggers? (Dumb question, I know.) Assuming the structural integrity of the outriggers are find and they are just a little saggy, are there any non-welding options to increase the height a little, such as bolting on a shim of some sort?

3) I got a screaming deal on POR-15 black. The problem is that it came in a gallon container. I have read that this stuff dries quickly, and that people tend to recommend getting this in pints / quarts if possible. Keeping this in mind, what if I were to pour the amount that I needed into a separate container to minimize the amount of air exposure to the gallon? Or should I just return the gallon and stick with pints / quarts?

Thanks guys. Trying to get my ducks in a row before I start the daunting frame repair tasks!

perryg114 05-16-2019 11:16 AM

You don't need to do much frame prep for the POR15. Mainly just get the big chucks off and any grease. The worse the surface the better it sticks. I would put the gallon of POR15 in Bell jars. It takes a while to use a quart. Once you open the jar, you better use it up. You will need at least 2 coats. Probably pint or 1 Quart jars.



Outriggers usually sag because the frame broke loose from the rear of the trailer or they have rusted to nothing. You can buy them at several places. Outdoorsmart is one of them and there are several others. You can also make new ones. Their purpose is to support the floor and to keep the shell from bowing out or buckling. So yes you need them. The main attachments of the shell to the frame are bolts at the front and back and usually a hold down plate attached to the middle sections front and back. This is a multi-year project unless you are retired.



Perry

mikextr 05-16-2019 12:32 PM

The wire cups hold the wires better than the wheels do but there will be some shedding. Probably a good idea to put down a tarp to protect your kiddos and the driveway.

JoleneAS 05-16-2019 12:53 PM

Thanks for the replies, guys. I'll distribute the POR15 into Ball jars. I know that it can be applied to rust and only to knock of the thick stuff, but there's a great amount of my frame that has silver paint and my understanding is that all paint needs to be removed before applying this. I'll lay down a tarp for sure. Great idea.

As for the outriggers, I know that the shell attaches through them and have already been removing the bolts that secure this. I guess my main question about outrigger sagging is how much sagging is tolerable? Is there any amount that is tolerable? I don't know how to weld myself and don't want to go broke on replacement outriggers and mobile welding fees. (I know Airstream restoration is super expensive but if I can save some money I will try!). :)

Thanks!

kidjedi 05-17-2019 09:03 AM

Not sure if it's an option for your location, but I say: get thee to Harbor Freight! Some things there (a lot, actually) are junk. But some things are perfect for people needing "one time" use. They have a "hopper" portable sandblaster that is great for what you're doing. The wire wheels and cups *will* she'd tiny metal wires everywhere. Two years ago I did some wire wheel work in the driveway, and I *still* get metal splinters in my shirt and back sometimes when I lay down to work in the driveway! If you can blast with a reusable media (you can use things other than sand like walnut shells) and catch it in a tarp for reuse, that is usually a better way to go (especially for the kids!).

Harbor Freight also has "chip brushes" which are crappy, disposable paint brushes, so you don't need to clean your brushes (POR15 can be nasty stuff!); you can just toss the brush. You will get some shedding though (bristles in the paint). Buy jars with lids from the thrift store for dividing the gallon.

Don't skimp on the outriggers and frame. Paying a couple hundred dollars for welding now to make sure your frame is solid will save you a lot of time, hassle, and money in the future! It's that whole "the guy who built his house on the sand" thing. ;-) Chances are you can find "somebody who knows somebody" that can weld and probably has a portable rig (most rigs have gotten pretty portable these days). Or maybe drive the frame to them if you still have the axles and wheels on the frame.


edit: Another thought... if you find someone willing to "deal" for the frame welding, they may also be set up to sand blast already, and for a bit more could save you a lot of time and mess prepping the frame. I know it's hard to justify spending money when it seems "easy" enough to do the work yourself, but that frame is one thing you really can't *return to* once you've got everything put back together!

suncoasteng 05-17-2019 09:34 AM

Rust on Frame
 
Pressure wash to remove dust, oil & grease. Let dry for a day
Next day use putty knife followed by wire brush, hand or drill wheel, to remove large portions of rust. Use compressed air to remove rust dust, then apply one coat of Ospho. 24 hours later, coat with second coat of Ospho. 24 hours later spray paint with Zinc Chromate Primer, when dry to touch, do 2 coats of Epoxy paint

tbashin 05-17-2019 09:50 AM

Wire brushes on a grinder is the fastest, but wires will shed. 60 grit sand paper works good on a 1/4 sheet sander. Wear a dust mask either way.
I've used POR-15 for years on all types of projects. POR-15 works best if you remove loose rust and dirt, clean and de-grease the metal, then use metal prep (like phosporic acid from a home improvement or paint store) which kills the rust so that it is no longer rust, use POR primer, then paint with POR-15.
Painting POR-15 directly over bare metal with some remaining rust will work too BUT rust will continue to grow under the POR-15 if it is not 100% encapsulated by the coating. Videos are on YouTube as proof.
POR-15 can be thinned 1/1 with a good automotive grade paint thinner (not the cheap stuff at the home stores) and sprayed with a Harbor Freight throwaway spray gun too.

POR-15 can also be revived in a can or bottle if NOT left too long to dry completely by thinning with acetone. It will start skinning over from the top where air contacts it. You can remove the skinned over material and add a little acetone little by little and STIR STIR until you get it to the consistency you want.
If it dries in the threads or rim of a paint can you won't be able to reopen it without breaking or tearing into the container so clean the lid mating surfaces 100% before closing.
...and don't get it on anything you don't want it to stay on like your driveway, clothes, skin, kids, dog, etc. Don't ask me how I know.

harryk 05-17-2019 10:14 AM

When you get to do the floor, use Coosa Board...will never rot.

JoleneAS 05-17-2019 10:49 AM

Thanks for the replies, guys.

I had actually looked at the small sandblasters at HF but figured it'd be so messy the neighbors would kill me. Is there any way to keep the debris contained? I am doing a shell-on for wait it's worth (I don't have room of assistance of other adults to operate a gantry). Since shell on, I figured sandblasting wouldn't be viable.

Has anyone ever used sandpaper flap wheels to grind rust / paint? I think I'll lay out a big fat tarp and go with wire wheel but if flap wheels work reasonably, maybe this is a decent alternative.

As for Coosa board, that stuff is crazy expensive and I'm not a huge fan of not being able to secure screws directly into it. I think since regular untreated wood lasted for over 40 years, using treated marine or BCX will be the route I go.

Thanks for all of the great advise guys! Always happy to hear more! :)

Eric 26 Argo 05-17-2019 02:53 PM

Couple of suggestion and pointers. Get an electric 4 1/2 inch angle grinder and use the twisted wire cup or the flap disk wheels (my preference). Once you have knocked all the rust off you will want to get the POR 15 wash and metal prep to prepare your frame prior to applying the POR 15 paint. The metal prep leaves a zinc coating to help prevent future rust. Don't be afraid of doing a gantry it only takes one person to operate and two people to build.

JoleneAS 05-17-2019 03:20 PM

Quote:

Originally Posted by Eric 26 Argo (Post 2242423)
Couple of suggestion and pointers. Get an electric 4 1/2 inch angle grinder and use the twisted wire cup or the flap disk wheels (my preference). Once you have knocked all the rust off you will want to get the POR 15 wash and metal prep to prepare your frame prior to applying the POR 15 paint. The metal prep leaves a zinc coating to help prevent future rust. Don't be afraid of doing a gantry it only takes one person to operate and two people to build.

Thanks much! I also purchased marine wash degreaser and metal ready surface prep as well. As for the gantry, the biggest issue is just space and a driveway that is just not suited for it (it's a slight angle, probably a 5-10 degree grade, and wouldn't be easy to position the trailer back underneath). Ugh... maybe I should just make an angled gantry and have the wife help me operate it... seems kinda sketchy though.

I'll try both the wire cup and flap disks... thanks!

89Excella 05-17-2019 05:38 PM

Harbor Freight also has a magnetic floor sweep on wheels that works really well for picking up all the little bits of steel from grinding and brushing operations. I use it whenever I have been grinding or welding out on my driveway to avoid the rust stains that inevitably occur on the pavement in the area where such operations are conducted. I also use it to pick up steel chips on the floor in the machine shop. Much easier than sweeping. It would make short work of picking up the shed bristles from a wire cup wheel.

Hermes 05-18-2019 05:02 PM

Avoid the metal splinters
 
I have found that the best tool for paint/rust stripping on metal is the 3M SandBlaster disk. There is a model with a shaft for drills, and a model for angle grinders.

Here is the angle grinder version on Amazon (also on Amazon.ca):

https://www.amazon.com/3M-SandBlaste...ateway&sr=8-14

Wabbiteer 05-19-2019 03:58 AM

I tried all the methods - if I were to do it again I'd find a place to sand blast it, spend the money and bring home a trailer ready to paint. It took 2 quarts to HVLP paint my 27' frame. Keep in mind aggressive abrasives remove good metal along with the corrosion, so coarse coal slag and the like should not be used.

Also know POR-15 'Metal Prep Metal Etching Rust Neutralizer' is the final word in getting POR-15 to bond forever though any 'alodine' treatment will add protection, avoid the off-the-shelf primer style, just want a watery rinse to leave nothing behind except zinc.

You might find some tips buried in the following posts, if you have questions just ask.

POR15 reality check --> http://www.airforums.com/forums/f36/...eck-49665.html

Hey y'all watch this... (shell game) --> www.airforums.com/forums/f36/hey-yall-watch-this-shell-game-83064.html

70's AS asphalt-based frame paint prep for POR-15 --> http://www.airforums.com/forums/f36/...5-a-26833.html


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