OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk How do I clean these alloy heads

Not sure if this is the right place to post this.There is getting to be to many forums now.Getting confusing.

Hi guys I need to get some advice.Currently I'm restoring a few mowers,but the one's that I'm up to now is the VC-160 Mark II & III.At the moment I'm up to doing the engines.All is going well except for the heads.Here I'll show you what the problem is.




As you can see from the one on the left,they are very dirty.Now if it was just moist oil on there then it would be easy,but it has been baked on so it is rock hard.How do I remove it?I'm trying to make these heads look like they are new again.I have tried using degreaser and that just shifter the top layers.Now I'm down to the hard crunchy stuff.Surely there is a better way than sitting there with a scrapper and screw driver, chiselling away.There would have to be some chemical that I could use.Please help me with some other faster and better way.

There are several methods for cleaning aluminium but the chemical ones are fraught with difficulty. I suggest you look at this:
http://www.enginebuildermag.com/Article/2601/cleaning_aluminum.aspx
The central theme is heating the parts to a maximum of 250 degrees C (preferably a bit less, but that is the maximum that won't ruin the casting) for some hours, to bake the oil out of the crud, then more or less dust the loose dried crud off. However if the aluminium itself is oxidised (metal surface itself is discoloured from extreme heat) it may still require glass bead blasting, or manual scraping, after it is cooked.

This thread should be in Repairs and Maintenance/Questions on Engines/Questions on Victa 2 Stroke Engines, Blumbly. There are getting to be a lot of forums, but they are not yet fully set up with their new structure. Hopefully people will find it easier to navigate than it was before, when it is finished. The idea is to have "a place for everything and everything in its place", so you won't have to wander around trying to find things. I'll now attempt to move this to the correct forum.

Thanks grumpy,(but after reading all that)requires equipment that I just don't have.I really need something that I can use at home.Some sort of chemical that I can soak it in.

I thought you might wait until the home management system was distracted by other interests and make use of the ordinary oven, Blumbly, for a test run on one or two heads. If it works, and you are still on your feet, you could consider procuring a surplus electric convection oven from a thrift store or flea market.

Chemical cleaning can be done but tends to eat the aluminium, leaving a rougher surface than you start with. The highly effective chemical products are also highly dangerous, requiring full protective clothing - and realistically, could never be used legally in industry outside a sealed protective cabinet. Here is what may be the most effective of them:

http://www.enertechlabs.com/Power_Clean_Acid_2033.php

Note that stuff is a mixture of hydrofluoric, phosphoric, and sulfuric acids with some surfactants (wetting agents). Hydrofluoric acid is a substance that makes chemists turn pale at the thought of using it (I may be exaggerating, but only slightly).

There are slightly less hazardous products that omit the hydrofluoric but still have phosphoric and sulfuric with surfactants:

http://www.jmnspecialties.com/list/jmn-products/general-cleaning/10-aluminum-cleaners-acid.html

More realistically, you might experiment with some more ordinary chemicals - hydrogen peroxide can remove stains from aluminium, but is still a hazardous material and won't cut through crud, just stains.

Generally, Blumbly, as far as I can make out, the people who use the extremely dangerous stuff like Powerclean are small businesses doing jobs like cleaning aluminium trailers and road-wheels, perhaps in disregard of both the law and ordinary social responsibility. Splash that stuff and you'll not only be blind, you'll look like a fully made-up actor in a zombie movie.

Thanks grumpy that gives me something to look into now.

Have you tried oven cleaner it works pretty good on steel just don't leave it on too long

Oven cleaner is normally caustic, and will oxidise aluminium to a white powder.

Hi to All, there is a company in Wagga that does seed blasting (as well as sand and glass bead) and apparently brings aluminium up like new...I will be taking my Model 5 Victa base and head to get done in the near future....I will post pics

Have you tried a product called alushine?

Hi Michael_xr8, no mate I haven't, but I see it's available at a leading auto store....I shall get some and try it.
Thanks for the heads-up.

Deejay, I don't want to rain on your parade (well, to be truthful I guess I don't much like parades, and I think rain makes them more amusing on television) but you might check out this information before you buy that product:
http://www.chemlog.co.za/msds/Alushine.pdf

Alushine is simply a dilute form of sulphuric acid with a small amount of bifluoride, and some wetting agents. It is similar to all the other acid cleaners we have discussed in this thread, but has only one of the acids, and not the most effective one at that.

Grumpy, thanks for that...you just saved me $20....Back to seed blasting it is then!!

I'm going to try cam cleaner on mine I'll tell ya how it goes mines just as oil as yours. I'll soak it over the weekend

Ok my head looked similar to the one on the left soaked it in cam products cam cleaner used for cleaning dry paint on spray guns, I left it soaked in for the weekend and looked the same till I got a paint brush and all the old oil just came off like brand new again! 😃

Michael, can you post some pictures please?

That product seems to be a fairly conventional paint stripper, being composed 60% of dichloromethane, with smaller amounts of other solvents and ammonia. I'm a bit surprised that it would be especially effective as a degreaser, but it certainly contains powerful solvents, and does not seem to contain acid:
http://www.gpi.com.au/msds/hcgw4.pdf

Remember that dichloromethane is quite unfriendly to living creatures - in tests it seems to have some tendency to be carcinogenic, and can cross the placental barrier. Its use in paint stripper is banned in Europe. For heaven's sake, don't have that stuff in the house if you have a pregnant partner:
http://en.wikipedia.org/wiki/Dichloromethane

I'll try post pics. Yeah we use it at work when the stupid apprentices don't clean out guns. It contains methanol aswell which is a very powerful cleaner.

It certainly looks clean Michael. Did you immerse that decompressor in paint stripper for a weekend? I doubt that was a good move, I think it has a polymer diaphragm in it.

Nah I'm not that stupid haha