Wapsaholics anonymous rides again...

Need to talk about the day's episode of Wapsi? This is the place to do it. Play nice! ^_^

Moderators: Bookworm, starkruzr, MrFireDragon, PrettyPrincess, Wapsi

Forum rules
When two threads are posted for a day's comic, the thread posted first becomes the starting post. Please delete the second thread and add your post to the first thread. When naming the thread: Comic Name YYYY-MM-DD
Thanks guys! This keeps the forum nice and neat.
User avatar
Opus the Poet
Posts: 2165
Joined: Wed Aug 01, 2012 12:24 am
Location: Surrounded by Hell
Contact:

Re: Wapsaholics anonymous rides again...

Post by Opus the Poet »

Sgt. Howard wrote: Wed Nov 17, 2021 12:18 am Annie sighed- "He actually has a library that outweighs most pickup trucks."
I suspect that barring calamity, most of the posters to this thread could make a similar claim about their personal libraries. I know the last time I moved the discarded books and magazines pile was about 2 tons. And I keep looking for stuff I know I got since then that seems to have vanished in the breeze. But I still have a couple of tons of books and other printed materials that I bought since the last move in 1994.
I ride my bike to ride my bike, and sometimes it takes me where I need to go.
FreeFlier
Posts: 2260
Joined: Mon Oct 26, 2015 11:33 pm
Location: Land of the webbed feet

Re: Wapsaholics anonymous rides again...

Post by FreeFlier »

Opus the Poet wrote: Sun Nov 21, 2021 9:38 pm
Warrl wrote: Sun Nov 21, 2021 6:53 pm Most obvious use is as an abrasive. . . .
The finer grades are used to polish really hard stuff like the tungsten carbide mirror I joked about, but also used in lapping compound. That is a vital part of rebuilding a cylinder head for an ICE so that the valves seal completely. Lapping the valves matches the surfaces to produce a gas tight seal that works even at the pressures and temperatures of a racing diesel engine. . . .
The traditional lapping compound for valves is emery powder in grease. Diamond dust was too expensive and unnecessary, because the valves and seats weren't that hard. Even modern valves don't need diamond dust, though AFAIK they don't use lapping compound any more because hard machining has gotten so much more capable.
Warrl wrote: Sun Nov 21, 2021 6:53 pm. . . I suppose you could burn it. Good luck designing a fuel delivery system that can stand up to it long-term though.
As long as it's not under pressure, it wouldn't be all that difficult. There would be some abrasion, but not an unworkable amount.

You wouldn't believe how abrasive human skin is, and we build things that handle that just fine.

--FreeFlier
FreeFlier
Posts: 2260
Joined: Mon Oct 26, 2015 11:33 pm
Location: Land of the webbed feet

Re: Wapsaholics anonymous rides again...

Post by FreeFlier »

Opus the Poet wrote: Wed Nov 24, 2021 4:00 pm
Sgt. Howard wrote: Wed Nov 17, 2021 12:18 amAnnie sighed- "He actually has a library that outweighs most pickup trucks."
I suspect that barring calamity, most of the posters to this thread could make a similar claim about their personal libraries. I know the last time I moved the discarded books and magazines pile was about 2 tons. And I keep looking for stuff I know I got since then that seems to have vanished in the breeze. But I still have a couple of tons of books and other printed materials that I bought since the last move in 1994.
I have a 5x10 (1.5x3m) storage locker filled head-high with boxes of books . . . and six-foot (2m) piles of books in my living room.

--FreeFlier
User avatar
Just Old Al
Posts: 1586
Joined: Tue Jul 31, 2012 4:43 am
Location: Wilderness of Massachusetts
Contact:

Re: Wapsaholics anonymous rides again...

Post by Just Old Al »

FreeFlier wrote: Wed Nov 24, 2021 8:30 pm The traditional lapping compound for valves is emery powder in grease. Diamond dust was too expensive and unnecessary, because the valves and seats weren't that hard. Even modern valves don't need diamond dust, though AFAIK they don't use lapping compound any more because hard machining has gotten so much more capable.

--FreeFlier
I might somewhat disagree here. While from a manufacturing standpoint I will completely concur, when rework is due lapping is still a quite viable method - and in my opinion superior to portable equipment.

Yes, cutters and such will work - I can hard-cut valves in my lathes and give you a lovely 45 (or 30) degree pitch. I can cut the seats with a portable cutter, as well. However matching them in my humble opinion works the best. Do the preliminary cuts, then grind them with emery in oil. You get a good, gas tight seal and one that's hard to beat given the inexpensive nature of the equipment involved.

Been there done this on many a petrol and Diesel engine and never had a problem, especially if the valve guides are inspected properly and renewed as necessary.

I can completely refurbish a cylinder head in an hour or two of pleasant work in my workshop, with no need for screaming machinery or external assistance.
"The Empire was founded on cups of tea, mate, and if you think I am going to war without one you are sadly mistaken."
User avatar
Just Old Al
Posts: 1586
Joined: Tue Jul 31, 2012 4:43 am
Location: Wilderness of Massachusetts
Contact:

Re: Wapsaholics anonymous rides again...

Post by Just Old Al »

Re: Library:

Yep, if rendered to paper a couple of tons would be about right if perhaps a bit conservative. However a flood in the late eighties destroyed my engineering and personal libraries, and I've tended to replace reference materials in a digital fashion rather than in dead tree format. Piles and piles of manuals are a lot less useful than rows and rows of searchable documents... :)
"The Empire was founded on cups of tea, mate, and if you think I am going to war without one you are sadly mistaken."
Warrl
Posts: 1629
Joined: Sat Jul 20, 2013 10:44 pm

Re: Wapsaholics anonymous rides again...

Post by Warrl »

... particularly if you have software that can search ALL the documents, for the times when you can't remember which manual something was in.
Post Reply