heavy rust removal (sandblasting)

[crazymike]

I have a large trailer (actually, it's starting gates for horses).

It's made of square tubular steel and sheet metal (1/4" atleast, thick++). It's approximately 9' x 25'.

It's in decent shape as far as starting gates go, but it needs some work. There is a heavy coating of rust in many spots. Not to the point where the structures integreity is comprimised, but a good amount of surface rust. Basically it's been living in a field for 10 years.

I was thinking of renting a heavy sandblaster and sandblasting the entire thing, but I have never sandblasted something this big. How far does a 100lb bag of sand go, and how much roughly does one cost? I will be doing this outside, so I can recover some sand, but not all of it. Also, do I want just sand? or something heavier? I'm not looking for a mirror finish, just a clean surface that will make this last another 10 years.

My other options are chemical, but I'm not sure how much this will cost. Is acid bathing expensive?

They look similar to these to give you an idea...

 

[rambler]

I have zero experience, but have heard it beats bits of rust into the surface, to come through new paint in this type of application. Chemical is better.

I'll eagerly look for replies, as I have a car trailer I've been trying to figure out what to do with. /forums/images/graemlins/smile.gif

--->Paul

 

[Spiffy]

Something that big would take a very large acid tank, so it might be pretty expensive.

As far as blasting, for anything you can likely rent it will take some time, but if you can get a pressure blaster (suction/gravity ones are simple and cheap, but you'll get more velocity at a given pressure with pressure), it shouldn't be too bad. Even with an 1/8 nozzle you'll want at least a 20CFM continous duty compressor (this will require 230V on 25A breakers) with a half inch hose. Don't forget good water knock out, or you'll have a mess too.

Figure a couple bags of sand per hour. I hate silica because wearing a cartridge filter gets annoying, but it cuts better and clogs nozzles less than "BlackBlast" [and the filter is a good idea anyway; who knows what dust the old finish is kicking up], so I use it. You'll also get an appreciation for a full hood and heavy rubber gloves.

 

[Clyde]

Mike - I don't know anything about the process but lately I'm hearing about soda blasting in vehicle restoration. Obviously, if a person does an off the frame restoration - he wants the best technology has to offer. By the looks of your photo of the "starting gate" that you want to turn into a sort of trailer - is the end result worth the upfront costs? Could a good hay rack trailer fill the bill? I like the low height of the bed but perhaps a round bale trailer would do just as well, with some modifications. The starting gate configuration of your someday trailer was built specifically for just that....a starting gate. Is it of sufficient structure to handle your needs without major iron added?

Best of luck in your project - Clyde

 

[crazymike]

</font><font color="blue" class="small">( Mike - I don't know anything about the process but lately I'm hearing about soda blasting in vehicle restoration. Obviously, if a person does an off the frame restoration - he wants the best technology has to offer. By the looks of your photo of the "starting gate" that you want to turn into a sort of trailer - is the end result worth the upfront costs? Could a good hay rack trailer fill the bill? I like the low height of the bed but perhaps a round bale trailer would do just as well, with some modifications. The starting gate configuration of your someday trailer was built specifically for just that....a starting gate. Is it of sufficient structure to handle your needs without major iron added?

Best of luck in your project - Clyde )</font>

I'm actually restoring them to continue their use as starting gates. We train and race horses.

I said it was a trailer for those who don't know what starting gates are. And esestially it is a giant trailer with a tongue, lights, etc...

A new set of gates is upwards of $10,000. A used one is around $5000+ and will still need restoration. I got those for a steal and are in fairly decent shape considering they have been in a field for 10 years.

----

I've checked online and I can rent a pressure fed sand blaster. There is some sheet metal in the horse bays which I won't sandblast (I want to retain it's shape) But the tubular steel is channeled, etc... and would be a pain to wire wheel. I'm not looking for a mirror finish, just something to preserve the steel for another 15+ years. Once I eliminate the rust I I can keep them in decent painted shape and store them inside during winter.

I can rent 100lb and 300lb machines that run off a compressor, I have to check what my compressor is rated at. Since I only have 115 amp service where I will be working on them I will use a large generator, so power is not a problem.

As for water, I don't really have a good source of water, there is a pond and I have a gas pump, but the water won't be that clean. However, I will be doing this outdoors in a field, not my shop.

 

[RalphVa]

You might want to try out a chemical that turns the iron oxide (rust) into iron sulfide (a very hard, black coating). Rust Oleum makes one called Rust Reformer; our local Lowes has it. You can get a similar kind at NAPA stores; forgot what it's called.

Even if you do sand blast or acid treat to remove the rust, I'd still use one of these to make sure you inert any rust that pops back, and a tiny bit will pop back immediately upon contact with air. It's almost like trying to keep grape juice from fermenting; it starts as soon as it gets to air.

I've used this stuff for a number of years. Once, I painted my snow plow but it got the paint rubbed mostly off on the plow surface. I put some of this on it, and it never did rust.

You can paint this stuff. You don't have to leave it black.

Ralph

 

[SPIKER]

first off heavy scale is hard to sand blast off, you have to first use a needle scaler to remove it. a heavy grinder with 36/24 grit wheel will work too for this step. sure a lot of the scale will come off with blasting under just the air pressure which is good but it will also waste a LOT of sand. there are rental places who rent gas/deisel powerd air compressors with the sand blasting eq too. much better as these are very high CFM devices. it may just be cheaper & wiser to look for a local sandblasing outfit. usually something like this can be done cheaper than renting the equipment a 20' tow behind eq/car trailer sandblasting around here is anywhere from 50 ~250 depending on how bad shape it is. this device (starting gate) would be in the upper range due to all the tubing surfaces.

after cleaned you difinatly need a rust destroying primer surfacer. many types and then top coat with good paint.

using silica sand (beach sand or play sand) is bad on the lungs (silicosous) spelling.? is a lung disorder which is like asbestose cancer. not sumthing to mess with. resperator is definatly needed... now

there is a 2nd option, if you have some old stuff that needs it and a good battery charger or welder you can make a bath that will remove the rust pretty quickly and will cover more areas (if you can submearge it it will remove 100% of the rust through chemical reaction. ) my old system had a ton of links but is lost due to MOBO & hard drive dies. /forums/images/graemlins/frown.gif

it is elctrolisis & rust conversion. I know you could find a lot about it looking / searching here & on-line too. I posted these links a while ack on here so I know it is here where I don't know though. I tried searching no-luck maybe someone has the link to it/them.

mark M

 

[Spiffy]

You won't need a water source; it is keeping it out of the lines (clogging your nozzle and creating surface rust on your new finish) that concerned me.

The size of the sand tank doesn't matter, but some brands have bigger hoses and bigger guns (for bigger nozzles [don't forget even more air!]) on the larger tanks.

If there is a blasting service around that'd be great; even if it cost a bit more than doing it yourself. Else, instead of the generator on a compressor [unless you have a monster compressor and 10Kgenerator], see if the rental place has a [maybe 20HP] portable trailer unit.

As others have noted, after you go through the work/expense of taking care of the rust; it's worth using a quality primer with rust inhibitor or similar prep coating. I'm also convinced a quality top coat beats doing it again! /forums/images/graemlins/smile.gif

 

[Spiffy]

Not sure about the condition of your car trailer, but the wife's horse trailer was full of rust, pitting in many places. I really wish we'd taken better pictures, but hindsight. We blasted and painted it to stop the rust [so our body work isn't nor was intended to be pretty], and it did very well. However, we did use "industrial grade" paint; muti-part epoxy based stuff if I remember right.

It's only been a couple years, but putting up with horse dung and gravel roads, not to mention always stored outside; I'd say is a pretty good test.

 

[Spiffy]

The outside, especially toward the bottom was much worse, but no picture. This one, I'm not sure if was taken right after blasting or priming. From 10 feet, I couldn't tell the difference with the gray primer we used.