Heating Iron Phosphate

[callmej75]

I have searched and searched and cannot find what I found last night. I want to use small amounts in a sprayer for iron phosphating small parts and I noticed last night that someone had mentioned some kind of spray setup with an inline solution cup or something to that effect that puts out small amounts of the phosphate in with the water. Anyone have a clue as to which post I'm talking about? Don't really need a heated tank at this time because its very few parts at a time. Thanks!

[bzer1]

Check your iron phosphate formula carefully. All the formulas that I've seen need to be heated. Most don't become reactive untill about 90f. There are a few conversion coatings that will work at room temp, but are usually brushed, or rubbed on. I've been using a product that can be sprayed at room temp but found that it's much easier to brush it on, or wipe it on with a lint free cloth.

[callmej75]

I ordered the caswell iron phosphate which requires heating. I use to use another solution when I did powder coating in Florida and we had a 220* hot water heater to heat up the solution but we also had a nice prewash station too!

[engineerscott]

I think this thread I started some time back may have the info you are looking for:

Anyone use the Iron Phosphate Primer?

BTW, I didn't have a Menard's store locally but was able to find the spray gun at Harbor Freight. Caswell's sells the ceramic immersion heaters that you will need to heat the solution. Let me know if I can answer any other questions.

Scott

[callmej75]

Originally Posted by engineerscott

I think this thread I started some time back may have the info you are looking for:

Anyone use the Iron Phosphate Primer?

BTW, I didn't have a Menard's store locally but was able to find the spray gun at Harbor Freight. Caswell's sells the ceramic immersion heaters that you will need to heat the solution. Let me know if I can answer any other questions.

Scott

Hey thanks Scott! That was the thread I was referring to. I'm wondering if some how I could come up with something to mix the solution with hot water coming from a hot water heater. Maybe some way of controlling the flow of solution feeding into the hot water that comes out of a sprayer.

[engineerscott]

Originally Posted by callmej75

Hey thanks Scott! That was the thread I was referring to. I'm wondering if some how I could come up with something to mix the solution with hot water coming from a hot water heater. Maybe some way of controlling the flow of solution feeding into the hot water that comes out of a sprayer.

I think what you suggest will have two problems (which may or may not be severe enough to make it unworkable).

Problem #1 - You really should be using either deionized (DI) or Distilled water both for mixing your iron phosphating solution and for rinsing the part. Impurities in your local water may cause issues (either scaling or corrosion). Your tap water will have varying amounts of chlorine, fluorine, calcium (mostly calcium carbonate), iron, and other minerals. Depending on the concentrations they can cause problems.

Problem #2 - You will not be able to control the concentration of the iron phosphating solution. To high of a concentration can definitely cause corrosion problems.

That said, what you suggest may work just fine. If you want to go this route I would go to a garden supply store and get a "hose end sprayer" which is normally used to apply fertilizer or chemicals to your lawn. They have a bottle that you put your undiluted solution in and it is slowly siphoned out and mixed with the water you are spraying. Hook this up to a hot water tap and you may be in business. If I had to guess though I would think that what would end up coming out of the sprayer is going to be considerably diluted compared to the mixing instructions of the iron phosphate solution. If you go this route I'd get a hose end sprayer that is made mostly of plastic. The plastic will not react with the phosphating solution.

The route discussed in that email is pretty cheap and easy if you have access to an air compressor. The engine sprayer is cheap (under $10 at Harbor Freight). Also, since you pre-mix your solution prior to spraying you know you have the concentration right. Of course, if you don't have access to an air compressor it is more tricky. You might find some sort of fluid pump that could pump the solution into a sprayer. Maybe you could pre-mix your solution and pre-heat it and dump it into a pump-up sprayer. You could make it a bit hotter than normal and it would probably not cool down enough to be a problem unless you were really trying to spray something huge.

FYI, here is the sort of engine cleaner/sprayer we are talking about:

http://www.harborfreight.com/cpi/cta...temnumber=3885

Here are the heaters to put in your solution bucket:

http://www.caswellplating.com/kits/ceramic_heaters.html

One or two of the 300W heaters (~$12 ea.) will do what you need. You can buy a temperature controller (~$17) and it will turn the heaters on/off to maintain a set temperature or you can just get a kitchen thermometer and do it manually.

I would really suggest if you go the route you are suggesting that you get some jugs of distilled water from a grocery store or walmart to do your rinsing. This would go a long way towards avoiding any problems due to minerals/impurities in your tap water.

Hope this helps,

Scott

[callmej75]

Originally Posted by engineerscott

I think what you suggest will have two problems (which may or may not be severe enough to make it unworkable).

Problem #1 - You really should be using either deionized (DI) or Distilled water both for mixing your iron phosphating solution and for rinsing the part. Impurities in your local water may cause issues (either scaling or corrosion). Your tap water will have varying amounts of chlorine, fluorine, calcium (mostly calcium carbonate), iron, and other minerals. Depending on the concentrations they can cause problems.

Problem #2 - You will not be able to control the concentration of the iron phosphating solution. To high of a concentration can definitely cause corrosion problems.

That said, what you suggest may work just fine. If you want to go this route I would go to a garden supply store and get a "hose end sprayer" which is normally used to apply fertilizer or chemicals to your lawn. They have a bottle that you put your undiluted solution in and it is slowly siphoned out and mixed with the water you are spraying. Hook this up to a hot water tap and you may be in business. If I had to guess though I would think that what would end up coming out of the sprayer is going to be considerably diluted compared to the mixing instructions of the iron phosphate solution. If you go this route I'd get a hose end sprayer that is made mostly of plastic. The plastic will not react with the phosphating solution.

The route discussed in that email is pretty cheap and easy if you have access to an air compressor. The engine sprayer is cheap (under $10 at Harbor Freight). Also, since you pre-mix your solution prior to spraying you know you have the concentration right. Of course, if you don't have access to an air compressor it is more tricky. You might find some sort of fluid pump that could pump the solution into a sprayer. Maybe you could pre-mix your solution and pre-heat it and dump it into a pump-up sprayer. You could make it a bit hotter than normal and it would probably not cool down enough to be a problem unless you were really trying to spray something huge.

FYI, here is the sort of engine cleaner/sprayer we are talking about:

http://www.harborfreight.com/cpi/cta...temnumber=3885

Here are the heaters to put in your solution bucket:

http://www.caswellplating.com/kits/ceramic_heaters.html

One or two of the 300W heaters (~$12 ea.) will do what you need. You can buy a temperature controller (~$17) and it will turn the heaters on/off to maintain a set temperature or you can just get a kitchen thermometer and do it manually.

I would really suggest if you go the route you are suggesting that you get some jugs of distilled water from a grocery store or walmart to do your rinsing. This would go a long way towards avoiding any problems due to minerals/impurities in your tap water.

Hope this helps,

Scott

Yeh I remember when we had issues in Florida with just using city water. We actually went to a high dollar DI system which may come down the road a little further. So if I mixed the solution in a bucket, heated it up, sprayed it, then let it sit and cool down and put a lid on the bucket then would the iron phosphate be ruined by the next time I used it or would it be as fresh as I used it the last time? Or would I have to change it out after every rinse? I am just going to do small parts for the time being so I really don't need to mix up a large quantity at one time. Thanks for taking the time Scott and helping me out! So you're an engineer ey? I am going to school for it now...30 yrs old and going to school! Gotta be done sometime....

[engineerscott]

If you mix it in a bucket and heat it and spray it on your parts I would think that any solution left would be ok to use again. The main component of the Iron Phosphating solution is phosphoric acid. It should not degrade easily. I might drain it back into a smaller container after it cooled down.

Yeah, I'm an electrical engineer. I design Fiber Optic, DSL and other telecommunications equipment. Been at it for 16 years now (boy how time flys). Thirty is definitely not too old to start working on an engineering degree. I have a good friend that I work with who started a EE degree program at 28. Have you decided on any particular engineering field?

[callmej75]

Originally Posted by engineerscott

If you mix it in a bucket and heat it and spray it on your parts I would think that any solution left would be ok to use again. The main component of the Iron Phosphating solution is phosphoric acid. It should not degrade easily. I might drain it back into a smaller container after it cooled down.

Yeah, I'm an electrical engineer. I design Fiber Optic, DSL and other telecommunications equipment. Been at it for 16 years now (boy how time flys). Thirty is definitely not too old to start working on an engineering degree. I have a good friend that I work with who started a EE degree program at 28. Have you decided on any particular engineering field?

Yeh I see alot of older people coming out to college now. Don't make me feel as bad! I thought about Mechanical Engineering and maybe opening my own 4WD offroad fabrication shop, customizing in 3-link, 4-link, and single axle swaps on the newer IFS trucks. Still analyzing it though and getting everyones input around in the area on how the business would take off. I do know I would like to have my own batch powder coating line someday regardless if this takes off or not because I love it. If not I was looking towards either Chemical Engineering or Environmental. Seems like the Environmental is a sure shot here in VA.

I was looking at a different gun at HF but the link you posted seems to be more of a better choice rather than the other. Does this gun operate on suction from the bucket with a feed line along with the air pressure? Distilled water will be bought at walmart instead of tap water.

[callmej75]

Ok I had a friend that lived near HArbor Freight that was gonna pick up that pneumatic cleaning gun for me but he ran into financial difficulties and is unable to make it up. Ordering this thing would take over a week to get because Harbor Freight takes forever on shipping. So does anyone else have any ideas on a phosphating gun?