stupid poly ethyl aminic stereo peroxides

Discussion in 'Off Topic' started by HeadSmess, Jan 25, 2014.

  1. HeadSmess

    HeadSmess Well-Known Member

    just one of those weeks, playing with timber. been blowing the dust out of the furnace, get back nto some ali castings.

    so i been making a pattern. its very easy to make a pattern. bit of timber here, whack it in the lathe there, measure things whilst making a mess with wood shavings...

    whats harder is taking a plaster cast of said pattern, as the pattern is simply the shape of a core piece, and making a negative mould is pretty hard, when it needs to be split perfectly down the centre! the negative is needed as its filled with sand, the shape is baked, removed, and inserted into the mold prior to pouring. i should get a sandy blob that resembles the current mess of timber and varnish i just took a cast of...

    ive made this same pattern four times now, and bought all the plaster of paris that the local hardware had in stock... had major release issues, to the point i was contemplating trying alloy work rather than timber.

    the final straw was when the fibreglass resin i painted it with last night still hadnt set this morning.... oh the stuff in the bowl and on the brush and bench and everything else went off like a dream, the smear i wanted to seal off the grain of a timber pattern? WTF??? :icon_bs:

    well, i had a tantrum, persevered, conquered :) finally was able to remove said pattern from the plaster, without destroying either the pattern or the plaster! grease, my boy, grease! so the core box is made, i can start on the nasty bit...the actual pattern! this should be relatively easy, as i dont need to take a cast of it...just ram it into some damp sand.

    oh, just an odd gunna make one of these if it kills me...

    mainly cus, if i can successfully do this...i can scale up the idea to a nice 60cc v twin type affair... :biggrin:
    Fabian likes this.

  2. Fabian

    Fabian Well-Known Member

    Ohh la la - - - :drool5:

    I want to get my hands on the V-twin, big bore version; ideally being compatible with the SickBikeParts shift kit.
  3. keatonx

    keatonx Member

    What part are you making?
    I once put a bunch of scrap of aluminum into a soup can and put it into a big fire, and I had to fan the fire for HOURS to even get it to melt! (I have no idea why did to just get some bricks and make a mini furnace) I needed the molten aluminum for something I was making, I don't remember what, but I ended up with a solid aluminum hockey puck!
    It was cool how all the aluminum oxide floated to the top.
  4. HeadSmess

    HeadSmess Well-Known Member

    currently, just the core box for moulding the sand cores.


    so. pictured. two core halves. for inside the crankcase.(see drawing....its a lot easier after redrawing on CAD mind you, get to see it in 3D!;)) timber. plaster of paris cast, the odd bubble filled with wax, given a quick spray of...why did i get matt black? back to the hardware store, i need gloss! or spray on estapol or something that will set like a rock...sand is abrasive, and while ths may only get one use...ive noticed, with much net surfing, that one company supplies castings.... general opinion is that theyre woeful for the 180 POUNDS or so they cost... the same mob tries selling those plans i linked to for 20 pounds! theyre available free, and all the errors are included, and the information is just as scant, being the exact same file! yes, theres at least three errors in those drawings! and the supplied castings of course...include the errors! one is 1/4" out! for a conrod...thats bad! (once again...refer to drawing, do the maths, and given conrod length is just not going to work!)

    i really need a new camera.

    so, i make the patterns :) even if my machining proves lousy...i can at least cast semi reasonably. this is my first attempt at anything involving a core piece but....eep :) havent even started! how to cast a piston? make the rings? all fairly easy with some research and thinking and then the fun part...having a go :)

    ill be using old engine parts from the scrapyard... germans tended to use good alloys, apparently. aluminium cans are the wrong alloy, and you get about 60% oxide/slag/useless muck...

    erm...lets see now... i did a lousy video once... just an open face mould, very badly positioned camera tripod. yes, i do all my dangerous stuff alone with no assistants! someone could get hurt!

    as for the vtwin...the ideas been lurking in my skull for a few years now, stewing away...not just an idle contemplation.

    for now, im thinking a basic engine, output shaft on either side, with no gearbox etc. but narrow enough to get between the cranks of a standard pushy, whilst being easily mounted. important features in my mind, after the great 4 versus 2 stroke debate. the HT wins for obvious reasons but loses in other areas...

    wanna make a non refundable deposit of $1000? :) remainder due upon completion :)

    cus, as one offs, anything under $2500 is sheer slavery(gets easier after the first one or two and you get jigged up...say, pistons...make a batch of 50 at a time...etc)...BUT. with a good design, enough volume of sales(or even interest)....could get say, huasheng to make em under license or similar... im actually considering ripping apart one (or both) of the huasheng copies i have of the eho25... use the valves, the cams, etc. saves a lot of work!

    or i stick with the fairly simple layout of sidevalves... reduces top power and all that, but i want reliability and simplicity, not performance! means i can just "copy" one section of the old ford v8...


    remove the "desaxe" offset, set up cams/valves to a sensible type of angle, etc...
    Last edited by a moderator: Dec 15, 2015
  5. HeadSmess

    HeadSmess Well-Known Member

    freaking internet. why do i spend half an hour or more trying to watch a one minute video?
  6. HeadSmess

    HeadSmess Well-Known Member

    the end result will hopefully resemble this to some degree...


    thats it, im ringing a certain provider and abusing them.

    "oh, no, it looks like you are in a bad signal area, it wont be upgraded for several years yet"

    you think id still be with the same company after four or more years if the reception was no good? after having tried everyone? no... one of your technicians left a hatch uncovered and theres water on the wires, thats whats wrong! the tower is only 2 km away!
  7. keatonx

    keatonx Member

    I'm eventually going to make an opposed or inline twin out of two homelite bandit trimmer engines. Was originally thinking about using ryobi 31cc engines, but they wear out somewhat fast. I have one on my weed eater bike right now and it's worn through the chrome plating on the cylinder with lots of aluminum showing, at it only has maybe 100 hard hours on it! Crank bearings are also on the way out, making it not stay tuned (yesterday it randomly quit and I had to carry it for 30 mins through a snowstorm!)
    I've had many,many ryobi engines on that bike and they all died for some reason or other, stripped spark plug threads, caught rings, broken crank etc.

    I've got a nice reed block and expansion chamber off a Kawi kd80x for this twin motor too, we'll see if one pipe works with two separate firing cylinders:jester:
  8. HeadSmess

    HeadSmess Well-Known Member

    yeah, pipes can work on multiple cylinders, but arent perfect,plus a pipe for 80cc is a pipe for 80cc...not 30 ;) not to mention the port timings or peak rpm... cylinder volume, not total volume! pipes are designed for the engine, not the other way round!

    ryobi, or anything with a single end crank are junk, no matter what brand. they can work well, but are usually just a sign of cheap manufacturing. junk :)

    only thing with two strokes and multiple cylinders is keeping either...both pistons at TDC simultaneously, or separate crankcases. would love to see inside one of the radials my friend has...a 3 and a 4 cylinder, both twostrokes...(possibly canadian but then the company was originally german, then italian, so who knows?)
  9. HeadSmess

    HeadSmess Well-Known Member

    now im ranting about spray on polyurethane :)

    despite 3 days in the sun, it remains just flexible enough to hold sand grains when you ram the mould down, making for a small pile of wet sand after removing...what remains behind needs brushing out then try again :jester: and after my chemistry experiment...i had to break it :) i did get one or two to pop out ok, but they werent rammed and fell apart when touched. but looked otherwise perfect :) i did get the draft angles right.

    so i just poured another cast in straight cement powder this time. should work. cheaper than plaster of paris and definitely has more working time. why do i buy things rather than use what i have plenty of? gee im stupid at times :wacko:

    now, my chemistry experiment! i made water glass :)


    sodium silicate. huh?

    :rolleyes7: some caustic soda (lye), some water, and silica gel beads(yes, also known as "dessicant", the stuff in lil sacks in pill bottles etc that say "do not eat"), dissolved over a bunsen burner.

    mix the sand up with this stuff rather than water. apply CO2, for nearly instant setting, or simply wait a day for it to dry, or even bake it on low heat for an hour. i let it sit.

    well, it sets like a rock :wacko:

    or more like soft crumbly mortar. just the stuff for making core pieces! it also seems to make a stickier moulding sand than plain water... so it really stuck in there! i need to get a bag of clean sand also, all i had lying around at the moment was brickies sand, which has (too much) clay in it, so is a bit too sticky anyway, and is far too coarse! it doesnt "screed" off smoothly like fine sand does. sometimes you shouldnt use what you have plenty of for good reasons :p i also need a co2 fire extinguisher...

    so i guess im going to try the nasty old polyester resin again on this new cast. or...i think i can thin JB weld/epoxy with acetone! i need something that sets! no flex! no tackiness! smooth and hard as glass!

    but, interesting...coincidence? my job today involved being in someones garage briefly as i trashed his house (seriously). what did i find? a mill. a lathe... a freaking STEAM TRAIN. another steam train... a massive bookshelf of mags... one of those model machinists, does all his own stuff. got his number, will try and have a good chat with him :) he left before we went psycho on his home, so i only spoke to his wife today.

    mainly, i want to scan all those old model machinists magazines, seeing as they arent available online! (bar one or two articles, as linked in my first post) i think its rude that people are making money from selling articles from a magazine thats out of copyright. not even their own work! the castings, sure... correctly redrawn and dimensioned plans, with clear instructions, photocopies? huh? go to that firey place! not sure how far this guys date back but i saw 1973 in there! the older ones are better than the new new new ones.
    Fabian likes this.
  10. Fabian

    Fabian Well-Known Member

    The CO2 thing sounds interesting.
    I want to see a video of that technique in action, with a really, really, really big CO2 fire extinguisher; responsible for creating a home town polar vortex :yes:
  11. HeadSmess

    HeadSmess Well-Known Member

    youtube :) "making sand cores" or something like that...

    not terribly impressive, dont even see anything! just awesome how FAST it is! perfect for us impatient types.

    the cement cast worked :) still, im really annoyed that im getting small (and not so small) bubbles, despite shaking, vibrating, tapping... meh! cement, i got half a ton of the stuff here to waste!
  12. HeadSmess

    HeadSmess Well-Known Member

    well, the cement seems to release without needing paint either... just a quick spray with silicone.


    just, um...let them go hard before attempting to remove, move or even look at... :rolleyes7: theres that impatience factor again :p

    this is meant to be one of the easiest parts, but life, as always, makes the simplest things nearly impossible and the impossible things are easy. typical. i used to take casts when i was in yr 5 without these issues! bubbles. hmmmph. anyways. looks like im almost there at last!

    i refuse to start the next part, the actual moulds, until i get some good looking core pieces! these have to be accurate cus theres nothing worse than spending a few hours machining just to break through where you didnt want to break through.

    next pic will be the fun part, melting stuff :) just so everyone can laugh when it explodes in my face :)
    Fabian likes this.
  13. HeadSmess

    HeadSmess Well-Known Member

    let me stand next to your FIRE!!!!!

    oh yeah. 39 C outside, what better way to cool down but by BURNING DIESEL AND SUMP OIL??? meh, without aircon, it nicer than being inside :eek:

    :biggrin: call me crazy, but i never had an issue standing in front of fires... i still dont like it when the suns too hot though :(

    i do need a decent camera, my phone has no USB, so transferring pics is a freakin nightmare. i had a bluetooth thingy for the puter at one stage but iunno what happened to it :(

    anyway, i fired up my old girl, and emptied out my crucible... had a few kg of ...erm...nondescript alloy stuck inside it...

    i do need a real graphite crucible if im going to keep this up, iron dissolves in aluminium, makes nasty intermetallic compounds... and at one point, reline my furnace... the last lot was too wet when i poured it, far too soft and crumbly. "friable" i think the word is... mixture of dolomite, fireclay, sand, and perlite. with just a touch of portland gp cement.

    i really enjoy this stuff, been a good year since i played gyro the pyro... i find fire quite relaxing :)

    oh yeah. pics. i did get some!!!!

    the furnace, old R22 refrigerant bottle.


    blowing flames from the bottom... its not as easy to light as it used to be, and so some diesel escapes down the drain hole...


    HOT!!!! i like her motion too... all swirly... looks like its dusk? well, its about 3pm... nighttime is a few hours away yet!


    erm...15 mins later... can just see it starting to go, that tiny lil silver blob in the centre. the sneakers are SAFETY volleys :)


    melting good now!


    and...just poured it into a handy bit of 5 inch concrete pump-line... the black flakes are from my steel crucible disintergrating...


    and... what i do with the last few dregs left in the pot...dump it on the driveway :jester:


    oh yeah. i have an old 500kg, 1000lb gas bottle here for later...for if i ever get into this stuff big talking 60 or more litres of melt at a time! yeah baby! :wacko: just waiting for it to air out before i attack it with a plasma cutter... i may be mad but im not suicidal! :wacko:

    now. i need some sand... really, i need a whole sandpit... safety first! dump a few kilo of aluminium at 6-700 degrees on wet concrete or rock or anything other than sand and you learn its a bl00dy stupid thing to do... ka-BOOM!
    Last edited: Feb 2, 2014
  14. HeadSmess

    HeadSmess Well-Known Member

    i got bored and actually poured something the other night. no two part moulds yet, still havent gotten around to buying any sand...

    so i just squished my core patterns in to the lousy sand i have, and did a quick melt.

    now i know why all the manuals say "dont fire up until moulds are ready"

    takes a while, making a good mould. so. overheated alloy makes a mess. goes all bubbly, pours like yoghurt. not nice.

    still, looks cool :)

    Fabian likes this.
  15. HeadSmess

    HeadSmess Well-Known Member

    time for an update. how time flies.

    stopped procrastinating and started making the main patterns.

    stopped when i realised id just stuffed up and now i want a scroll saw.


    this was just balsa wood. i cut too accurately! forgot about the 3 degrees of draft required so the darn thing will release! sanding clearance. blah blah :)

    so i was going to set the jigsaw up, upside down, tilted over slightly...then had to buy blades and checked to see how much a scroll saw is...just did that yesterday :) now i WILL set the jigsaw up! (maybe theres an old scroll saw at the scrapyard! oh MY!)

    also bought some sand, and some bentonite clay (expensive kitty litter, the clay to use)

    now, one would think that mixing dry sand and clay together then dampening is all thats needed. thats what most foundry related articles say.

    so, i couldnt quite stop this stuff from being "sticky". add some water, add less water, add more clay, add more sand... just stays the same, sticky, too sticky and stickier...

    more research.



    so. basically you gotta rub the stuff in. like butter into flour for making scones! without the tasty stuff at the end.

    the experiment with a small handful resulted in a sand mix of an entirely different structure! what was sticky and horrible became something resembling gritty plasticine! i admit, way too much clay at that point.

    a sand mould is delicate...but is also surprisingly strong, nothing like a sand castle at all! (except those cheater ones full of binding agents)

    this IS a learning curve :)

    i still hate timber work, hence the procrastination....
    Fabian likes this.
  16. Fabian

    Fabian Well-Known Member

    I love this thread.

    Now picture me saying those words in Steve Ballmer fashion:

    Last edited by a moderator: Dec 15, 2015
  17. HeadSmess

    HeadSmess Well-Known Member

    2nd hand scroll saw...purchased.

    i really want this one but... well worth the money, just on the other side of the country :( ish bewdiful :)

    old maple shelving...perfect for patternwork!


    semi mulled sand works better than anything else ive tried so far. for a quick trial im pretty smitten :) no release agents, no shellac or varnish. and this pile of sand is actually hanging in that box! i didnt backfill to the top, as it is only a quick trial ;)

    this pattern is slightly tricky, in that it needs two cores. one ive already done, the other part... has to fit in the end, creates the mounting lug, and the overhang for the cam mounting. that raised section, once cast, should be a flange about 5mm thick. the rear face comes in another 15mm from the existing edge.

    also need to add the lug pieces for the oil filler etc.

    now. i need some timber drills. sharp spades. i found borers/twists just grab and destroy an hour or twos work...

    been thinking i might remake my core box too, screw the cast, just make it segmented from several chunks of wood. dowelled together for assembly.... thinking...

    mulling sand is also hard work! i see the logic in making a machine! apparently fairly easy. big roller, in a drum, slightly skewed so it "scrubs", some sort of spring on it so the "weight" is variable... some blades to scrape the stuff and mix it up after the wheel squashes it...

    ah, finally had a few good weeks work, waiting for the card to load up then...i have to buy neo magnets, dont i? one must keep several projects going at the same time :)
    Last edited: Feb 22, 2014
  18. HeadSmess

    HeadSmess Well-Known Member

    lil bit more work done....

    got most of the outer patterns done. few finishing touches yet, its really tempting to set the mill up again... manual labour hurts.


    still need to add the final bits n pieces... dowels and bosses and stuffs... i realised the other night i could make this thing as ohv with minor changes. but why bother?

    but nice to know it seemingly fits...

    Fabian likes this.
  19. Fabian

    Fabian Well-Known Member

    More sir, can we please have some more !!!

    This thread is intoxicatingly good. I can't wait for the next installment of the ongoing technical developments.
  20. HeadSmess

    HeadSmess Well-Known Member

    ahhh shaddup...

    bitter sarcasm ruins my appetite or summink.

    now, imagine the next one, with the timber replaced with a bonded sand core...


    thats about it for now. still obviously missing the valve/port area... bit of glue for that one. therell also be that other little core piece following the contour of the timber.

    i found a cheap source for now im setting the mill up. about time. need it for the other core box.


    sand still isnt right. im going to have to make the machine, cus doing it by hand is a nightmare!