Engine build cleanliness.

[Bellow]

Hi to everyone.
I am hoping that some forum members here can help. The objective is to create a clean (or cleaner!) environment in which to assemble components that seem so far to be troubled by the lack of cleanliness.
I know quite a few of you are involved in engine, and presumably transmission, building for competition, LSR, etc, vehicles where cleanliness is essential.
So here's the question. How's it done?
Presumably it starts with a super clean enclosure, but how is that initial cleanliness achieved then maintained?
Looking to construct an enclosure large enough to be entered by at least one person, so filtered air seems a reasonable place to start, or should I be considering excluding personnel and constructing a sand blasting type cabinet?
Any advice on what I should be looking to do and where I might source the necessary hard ware will be greatly appreciated.
Thanks in advance.

 

[Number_Cruncher]

What are you thinking of doing in the "clean room"?

The usual way to make a clean room is to specify all the materials in the room to be hard and non-shedding.

Then, you supply air to the room via a hepa filter, making sure that room ends up at a small overpressure, so when the door is opened, clean air goes out rather than dirty air coming in.

People are one of the big sources of contaminants, so, if they must go in, clean room clothing is required. Depending upon the class of cleanliness you're after, this can vary from smock, shower cap, and overshoe protectors to the fully enclosed suit. Removing any clothes which would readily trap dirt, like wooly jumpers is also a good idea.

Usually some form of access control is needed. If you're the only person using the room, then a quasi clean anti room with a tack mat and changing facilities will be enough.

This company supplies a good range of products

Guardline Technology | Guardline clean room supplies

Maintaining cleanliness is a matter of discipline. Every item being taken into the clean room should be cleaned in the ante room. For example, before going into a class 100 cleanroom, parts will go through a multi stage cleaning process where they will be cleaned by solvents, surfactants, by ultrasonic cleaning, and then a final solvent clean.

Some materials must be banned, from the obvious, like wood and paper (non shedding clean room paper is available), steel which may corrode and shed rust, to less obvious ones non-anodised aluminium, etc, etc.

If the work involves any delivery to a customer, you may also need to consider how cleanliness will be monitored and how it will be demonstrated to the customer. Witness plates, exposed in the clean room, and particle counters can be used.

If you're setting up such a room, it's worth also considering making it ESD safe, which may allow you to do some (clean) work on electronic parts also.

It's much easier to make up a clean cabinet, where you form the back wall of the cabinet with a hepa filter and fan, with the sidewalls made of polycarbonate, and the base made from stainless steel. If the cabinet is kept in a reasonably clean room, and you use gloves, and keep your hands and arms downstream, you can acheive surprisingly good results.

 

[kth286]

Hi to everyone.
I am hoping that some forum members here can help. The objective is to create a clean (or cleaner!) environment in which to assemble components that seem so far to be troubled by the lack of cleanliness.
I know quite a few of you are involved in engine, and presumably transmission, building for competition, LSR, etc, vehicles where cleanliness is essential.
So here's the question. How's it done?
Presumably it starts with a super clean enclosure, but how is that initial cleanliness achieved then maintained?
Looking to construct an enclosure large enough to be entered by at least one person, so filtered air seems a reasonable place to start, or should I be considering excluding personnel and constructing a sand blasting type cabinet?
Any advice on what I should be looking to do and where I might source the necessary hard ware will be greatly appreciated.
Thanks in advance.

You do not have to go to that trouble to build a car engine.

Cleanliness is about making sure that each component being assembled are clean ie. wiped with suitable non fluffy cloth or similar, the instant before it is assembled and suitably coated with clean oil if appropriate.

oilways should be paid particular attention with small long thin brushes and blown through.

the lighting should be good

 

[Satch]

You really do not need to go OTT but in terms of how easy can it be:

The patented Clean Tent inflatable clean room, can be erected in 15 minutes to give a class 1000 cleanroom. Next day deliver usually available within Europe.

Entirely possible to DIY something not that much less effective with some PVC sheeting, poles,and a suitable fan/filter arrangement

 

[Bellow]

Thanks to all (so far!). Should point out that it isn't actually an engine being built here but downhole tools to operate 3km beneath sea level. Hydraulic system, but I guess I asked the question the way I did because I thought engine builders would be best placed to answer it.
It's on behalf of a friend who works in the industry and feels levels of cleanliness aren't what they should be and is looking to improve the situation that I am asking.
I'm waiting confirmation, but I think it is NAS 1638 level #8 that is sought here.

 

[Number_Cruncher]

>>NAS 1638 level #8

That's helpful. The clean room practice I've described is roughly between class 100,000 and 1,000. Alas, there isn't a direct read across between standards.

To get beyond class 1000, you need to become*very* fussy and pedantic about materials, procedures, etc.

While the classes I've been talking about give maximum limits for concentrations of particles of various sizes per unit volume of air in the clean room, you're more interested in the contamination of a particular component. This then becomes a sort of probabilistic integration of the exposed area of the part and the time it has been exposed to the atmosphere. In this regard covering parts in very clean conditions when not being worked on gives you a real benefit.

If the parts are small, then, it's likely that a local very clean cabinet might be useful within a lower class larger clean room, with parts being stored under cover in very clean containers, or even under oil when not being worked on.

If there's no general access to the clean room, that's a big help. If a number of different people must go in, then, it's difficult to make sure that they all follow the "rules".

In the case you describe, I would imagine that regular indpendant contaminant testing of oil that has been flushed through the parts will be required to satisfy the customer. Clean facilities can also be audited by an independent inspector which might help in matters of customer acceptance.

What are the current working practices and conditions? These sound like high value parts, with a high requirement on integrity, so there should be scope for investement in appropriate facilities.

 

[grober]

This article might be of interest also. What Happened to NAS 1638?

 

[Bellow]

>>NAS 1638 level #8


What are the current working practices and conditions? These sound like high value parts, with a high requirement on integrity, so there should be scope for investment in appropriate facilities.

Once more thanks for all the contributions.
It has been confirmed that it is NAS 1638 that is relevant, and working to levels 8 and 9. Apparently level 6 is cleaner than required, but 8 and 9 need to be achieved.
In answer to the last question there - not a great deal, or not enough! Said mate will looking at this tomorrow and I suspect that some ''investment in appropriate facilities'' will follow pretty rapidly!
To give a little bit more info here, the problem is getting novel tools to operate reliably. There are a number of possible issues and none can be addressed individually without going through a process of elimination. So, next on the list is cleanliness during assembly. Once that has been attended to, any remaining problems clearly emanate from a different source. But until the cleanliness issue is resolved there is no point in looking elsewhere. Thus, achieving cleanliness has become the highest priority.

 

[Number_Cruncher]

>>So, next on the list is cleanliness during assembly. Once that has been attended to, any remaining problems clearly emanate from a different source. But until the cleanliness issue is resolved there is no point in looking elsewhere. Thus, achieving cleanliness has become the highest priority.

That sounds entirely rational and logical to me.