Plastics in the Dishwasher?

PetFish

New Member
Jul 3, 2019
9
1
3
For the first part of restoration, is it ok to put the plastic parts into a dishwasher instead of hand-scrubbing and rinsing?
 

PetFish

New Member
Jul 3, 2019
9
1
3
I'm just worried about the water temperature. I have no way to tell our machine what to do. I'd really love to clean the keys in the dishwasher instead of by hand.

Also, why does 8-Bit Guy use the hose and hand-scrub his stuff and not use the dishwasher? He must have a reason.
 

Markeno

Member
Jul 19, 2019
98
40
18
hobbytronics.home.blog
I guess different dishwashers will get hotter inside than others. Mine makes my counter quite warm. I wouldn't risk it. My concern as well would be melting, or even some deformation. Different plastics have different melting points. Printed Key Labels, may also be removed in the dishwasher. Having cleaned a few C64s, it is not that bad hand scrubbing the and the keys. Then no risk of causing the keys or case to deform. If you were to put the key caps in, they would be flying around inside there unless the plungers were still attached, but you wouldn't want the pads on the bottom of the plungers, they could come off and get lost, and if they didn't, they may no longer be properly conductive. The springs shouldn't really be left in there either, your mileage may vary though.
 
  • Like
Reactions: PetFish

Aramis

New Member
Jan 29, 2020
18
4
3
I guess different dishwashers will get hotter inside than others. Mine makes my counter quite warm. I wouldn't risk it. My concern as well would be melting, or even some deformation. Different plastics have different melting points. Printed Key Labels, may also be removed in the dishwasher. Having cleaned a few C64s, it is not that bad hand scrubbing the and the keys. Then no risk of causing the keys or case to deform. If you were to put the key caps in, they would be flying around inside there unless the plungers were still attached, but you wouldn't want the pads on the bottom of the plungers, they could come off and get lost, and if they didn't, they may no longer be properly conductive. The springs shouldn't really be left in there either, your mileage may vary though.
One can get mesh bags in the laundry aisle at many major chains... they're intended for washing lingerie, but work nicely for small silverware, so it should be no problem to load it with keys.

Likewise, there are closable cages intended for things like bottle caps and nipples. As long as the air-dry setting is selected, the dishwasher isn't going to exceed 100°C¹. The issue isn't whether it melts, but whether it is deformable, and most computer parts aren't deformable below 100°C. A few are, but the sign to watch for is the recycle triangle with a 4; LDPE often melts between 105°C and 115°C.

Heat dry often heats past 125°C, and more importantly, has some air flows well above that, and so shouldn't be used.

¹: The maximum pressure I've seen in a dishwasher was just barely over 1 local atmosphere. If your dishwasher doesn't kick the door open the instant the latch is released mid-cycle, it's pretty close to local. Likewise, the water really doesn't work better above boil; 95°C to 99°C keeps it liquid, and thus having really good force transfer.
Steam cleaning is usually done with a wand, and a sealed reservoir that generates 5+ Bar pressure by use of a pinhole nozzle. Works great, but isn't how dishes are normally washed.
 
Last edited: