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Hi. I’m interested in restoring some outdoor chairs, made from steel.
They may be galvanised, I’m not sure, but there are rust spots. There are lots of layers of paint - it’s really thick in some spots. So the issue is getting both rust and paint off.
Any suggestions. Preferably ones that don’t involve sanding or wire brushing. They are not worth doing if it involves lots of manual labour.
Cheers
Arron
(a) Solid or (b) tubular?
(c) Easily able to be taken apart or (d) not?
If its b & d there's probably no easy way and probably not even worth it.
If it's a and c maybe electrolysis? in a plastic lined box or crate? It will eventually get even thick layers of paint of.
Maybe some pictures would be useful?
A and D.
Yeah, I had thought of electrolysis. If I had a large tub, and expected to do half of each chair at a time (based on the largest plastic tub I have) will I be able to do the electrolysis using an automotive battery charger?
I’ve only used electrolysis on objects up to the size of a no 5 plane, so not sure how well it scales up.
Design-wise and quality-wise they are worth it - I’m just limited in the amount of manual sanding/scrubbing I can do.
Cheers
Arron
Sand blasting. Downside is access to suitable plant or cost.
A good way to remove rust, paint, galvanizing etc is to dip the metal object in a molasses solution. I used to use about 5 lt of molasses in 100 lt of water.
More molasses will probably speed up the process but its not worth the extra cost. It takes time but requires no effort. Lift it out occasionally to check on progress and make sure that when it has finished to protect the steel as it will rust immediately.
This method is used by antique car restorers as it won't affect the metalwork just leave it spotless.
Two step process.
1. Paint stripper. The thick orange environmental friendly type. Or a harsh chemical one. Your choice.
2. A good rust remover or converter.
You will need to scrub or scrape and sand to get a good finish.
A good undercoat and primer. Sand smooth then the finish of your choice either brushed or sprayed.
Photo of chairs as always helpful for us to help you.
Lyle.
The quickest way this would be done by pros is by sand blasting.
It depends on the value of the chairs but you may be able to find a sand blaster service near you that will do this VERY quickly and not that expensively especially given the time, cost and agro of setting up electrolysis and solutions etc,
It scales up fine but the larger size and then fact that you want to removed caked on paint, adds complexity.Quote:
Originally Posted by Arron
An it depends on the charger.
Auto battery chargers supply around 14V which is on the high side, and you will need a reasonable concentration of electrolyte to soften the paint, and together this will draw a large current which some chargers won't like and auto cut out.
The 14V and large container you will need also generates a lot of Hydrogen (ie dangerous so a ventilated are or outdoors operation is needed) as well as making a real red/gooey mess of the positive electrode (workpiece is connected to the negative electrode). The gooey mess will eventually insulate the positive terminal and stop the electrolysis. The Gooey mess has to be physically removed with a rag.
A better way is to
a) use a lower V ~6V
b) use graphite positive electrodes - no red gooey mess, no wiping of electrodes needed.
One of the safest electrolytes to use is Sodium Carbonate, (foot bath salts available at coles for $5 a bag). Unfortunately this doesn't soften the paint that quickly or some paints at all.
The residual electrolyte can also be safely disposed of down the sewer.
To soften/dissolve the paint it would be better to pre-soak in a Sodium Hydroxide (drain cleaner) bath which requires considerable care as it is highly corrosive.
Once the paint is off, an alternative to electrolysis is to just rust convert using Molasses but that will take weeks.
Evaporust is more expensive but very quick.
A cheaper alternative is Phosphoric acid based rust converter.
But maybe look and see what a sandblaster will charge first
Take it to a steel fabricator, for the cost of a slab or 2 of beer they will sand blast it.
I reasonably certain that the major hire companies do sand blasting kits for hire.
There is actually a place near here that advertises sand and soda blasting services. I’ll give them a ring.
Cheers, and thanks for the replies.
Arron
+1 for sandblasting, just don't try to blast aluminum or you'll have nothing left to pick up...
I don't mean to hijack this thread, but Aarron seems to be sorted... I have a box section steel post I want to derust. Are those flap wheels the thing to use (what grit?) or is a wire wheel better? Hand drill or angle grinder?
Thanks,
I'm pretty sure most Powder coaters have sand blasting ability . Then they can powder coat them for you as well ?
Franklin . Wire wheels are good . Check out the Band saw table top I just de rusted.
Take care if you have never used one though . They are good and grabbing, kicking and throwing dangerous projectiles of wire all the time.
Post 34 here
https://www.woodworkforums.com/f299/w.../3#post2066162
Rob
Thanks Rob! Interesting rebuild you've got going there. Wire cup it is then.