Wasn't going to update this today but I will anyway.....still no sand. Im going to have to ring 'England' Monday and see what the hell is going on. I haven't an ounce of sand left even to do wash or glue testing not to mind make the two cores for the first mould. Its been ordered now since the 12th so its gotten to be a bit of a joke now. Im really going to have to find a place in Ireland soon but anywhere Ive rang so far are a bit out of touch with tech terms ''What do you mean - grit size'' was one response. Its a bit of a pain considering how fast I did everything else, seems a bit of a waste now - I could have taken my time I might video the pour depending on when the sand arrives, and how Impatient/thick I am after that! Brian,
Try these lads Bri http://www.appliedpi.com/ , I could prob pay for and collect it for you if they can help. Less than 20 miles from me. Anywhere in Norn Iron'?
Was onto that crowd a good while back - they can no longer offer Silica sand as its now considered too dangerous for blasting due to fine particles given off and them causing silicosis. Im going to have to just believe this and not wonder if the guys going to die at 85 from something anyway So all they offer is powdered glass now. This is not suitable as it contains a lot of other things as its made from 100% recycled glass - I cant remember all the other things but Sodium Carbonate, Magnesium, and in this case Im guessing Iron Oxide(green tint) are probably present in there too. Thanks all the same though...! Brian,
Me included!! Ok, so I forgot about the small issue of testing the mould coating and core adhesive in my excitement when the sand arrived. I could skip this but it would be stupid to do so. So, with that in mind I tested both this evening to make sure nothing funny was going to happen with the new materials(have not used these brands before) So the first up was the mould coating(GZA4), as mentioned this is graphite and zircon talc in an alcohol suspension. It comes as thick paste and you thin down to whatever you like with the iso-Al. I took a while longer than my normal paste to get it mixed fully/thinned down but it holds in suspension far better than the last stuff so this is a good thing. Here is said coating ready for thinning, here its as thick as toothpaste, I dont have an image of it thinned, but its about the same as car paint now. I had to do a pair of very basic test moulds so here is what I used, The cavity is going to sit above the parting line in order to trap air in the cavity - this is one of the tests to see if the coating makes the sand airtight. Airtight sand is not a bad thing, but its good to know so you can add vents if needed. All the mould coatings Ive used before have made the moulds air tight so Im guessing this one will too. Here are the moulds, the bottom sections - the drags are just flat surfaces, Here I have brushed on the mould coating. Its then lit to burn off the iso-Al. Same with the drag piece, The other test mould is left un-coated bar the runner as below. The glue is then applied around the edge and the flat drag pressed on, I chose not to let the glue dry and pour right away - that way testing for water in the wet glue(steam) Its just weighted down and poured @ exactly 700 degrees C. This is a little higher than I normally pour but its what Ill be pouring the manifold runners at as they are long and the alloy needs to flow a good distance from the gate. Both moulds are poured, the set with the X is the coated one, First the un-coated on is broken open - the glue is fine, no steam or explosions even when wet, The part is a bit dull as expected with some sand sticking, Next, the coated mould, Great shine, no sticking, Coated on on the left - you will notice the corners did not fill out. This is normal with mould coating as they make the sand airtight as mentioned. Vents on high/air trap locations look after all that - Coated, Un-coated, That concludes the mould coating and adhesive test. The one other test Im going to do tonight is to see how long the glue takes to dry at workshop temperature. It runs at about 16 degrees most of the time so Im hoping it will dry fairly quick. Im going to coat the first set of moulds now and get stuff laid out ready for the off at long last! Brian,
No lsd needed at all in fact!! Thats some video - fire everywhere, have you no faith!? lol Why is it when one guy builds something in his garage that he cant buy hes a lunatic, but yet groups of people building the same things day in day out in a factory are considered perfectly normal? Something odd there dont ya think lol Im currently waiting for glue to dry, its not looking good for tonight as it is gone a bit late for casting now. I ended up putting the mould coat into an atomizer bottle and low and behold it sprayed it on perfect. I was eyeing up my Devilbiss HVLP gun but couldn't bring myself to do it. Iso-Al didn't melt bottle/pump so that was a plus. The Iso-Al is not as flammable as I originally thought and you dont even have to hold the cigarette behind your back Brian,
How have i not seen this before? i just read through all 6 pages of this tonight and it seems as though i have timed it almost perfectly. i feel sorry for all you poor buggers that have been in suspense this whole time, someone in somerset surely put brians sand in front of their house lol i definately cant wait to see this finished, and i cant wait even more to see what it can do when attached to JENVEE. you have some amazing skill, also that is a LOT of content, pictures and words, which must have taken a lot of time! I for one definately appreciate the time and effort you put into this project and thread. a very interesting read! i will more than likely want one of these at some stage
Thats what I like to hear lol A few shots of them with coating applied, you will only see them open one more time when the cores go in, I kept the wash off where the cores sit to allow them to breath into the vents(yet to be drilled) The wash has smoothed the surface a lot, so thats good(and its purpose!) And last, the mixing stick - held it infront of the heater to do a drying test initially after mixing - its almost fire proof now too, showing no signs of charring after a minute infront of the heater outlet I might paint it onto my face tomorrow lol Brian,
Well I doubt you'll want one if it shows no gains, but lets see!! Im glad you found the party in time, its just getting to the tense stage now and all lol Brian,
So, just to confirm, the lack of coating is enough to allow the air to escape into the sand on the uncoated mould, hence the sharp corners on the `high` points which don`t have trapped air without the coating ?
The good kind of lunacy, I meant though! They say there's a fine line between madness and genius...you're the right side of that line...! When I get my new garage built there will be all sorts of (good) lunacy going on. I'm after building a jet turbine from an old turbo, just for the craic, and probably a pulse jet too, again, just to freak out the neighbours with the noise. If you haven't seen the Colin Furze channel on Youtube, check out his pulse jet kettle, the "Jettle"...making brews will never be the same!
Sometimes I wonder about that bit lol I saw Colins antics alright - funny you should mention it as he came up on the Ferrari forum just yesterday. He was taking the decorations off a Christmas tree with a chainsaw lol lol . He really needs to lose the tie though or someday it will get sucked into one of his turbocharger jets What sort of science did you put into the combustion chamber on yours? I always wanted to build one but could never settle on a 'perfect' chamber design(if there is one!!) So, I finally got it poured, all went went and there was no hiccups Actually, the whole thing was not stressful at all actually, as it all went together just grand. The one thing I am short on is pictures - I had everything organized but forgot to charge phone. Ive only one USB on the mill and the keyboard is plugged into that so it gets interesting if you use that to charge the phone ANYWAYS, fear not, theres three others of these to do yet so I might use my 'real' camera for those and maybe do a video too! So here we are, I know some of you have been looking fwd to these so I guess its about time you saw them given that you all stuck through the boring phase of the pattern making As mad as it sounds I think that the moulds for a cylinder head are about three times easier to make and design than these so worth keeping in mind too given that you all got through the pattern making bit lol The cores installed, I have no pictures of making the cores but Ill post that when doing the other three, small wedges are used to hold them in place as the glue dries. I forced the glue dry with the torch and it bubbled a bit but the next three will air dry naturally since I now know the mould is sound, Here is the mould built, notice the dip in the top mould - this is when I ran out of sand and just made a crater there - thats how tight it was! Theres a few vents drilled too and I raked in auxiliary air vents on the ends of the runner which you will see in the next photo. I figured these would be a good Idea and a good indication too if the mould filled. Im going to add these raked shapes to the top mould box on the other three runners so that I wont have to rake them out every time, One other thing I did was to open up the moulds so that I could see the ends of the cores. This way I could just pack in some oil bond sand to make sure metal could not seal off the ends of the cores if it made its way up around them. A sealed core cannot vent and will burst. As it happens, no metals made its way up to the ends of the cores so I probably wont bother doing this on the others. Its important to cover all possibilities in the first run so that you can subtract as you go, and not have to come up with further solutions as you go(and at the same time keep failing). Here it is just poured, this is where the phone started batt low warning so the rest of the set is a bit rushed, The sprue shrunk down nicely, I figured at this point it was feeding the runner and riser which it was as the blind riser didn't shrink at all, Here it is after a minute of hammer and chiseling, you can see the added raked in risers, and also the ends of the cores free from metal. If you are ever casting anything its VITAL to keep the core ends open and not encapsulated There is also .5mm of flash off from the runner sides but this is not an issue, it just gets cut off. On the next ones Im going to put a line of glue there to form a barrier, A shot of the filter, spot also some metal came out from the riser along one of the co2 vent holes! A cross-section shot, Flange end, spot the two 3mm drilled vents here - since this was an airlock point at the top of flange, I drilled through the mould coating to allow air to escape into the mould - Fillet detail, Plenum/CF runner over rocker end, Runner/riser, spot the drilled vent here too through to parting line above - Gate detail, you can now see a lower than flange thickness gate gives you a guide line for cutting along, Flash zipped off rough with coping saw and offered up - hopefully giving you an Idea! You can see the machining hold down tab there too if you look really hard - Last shot of used mould, Id nearly say if you were using very simple moulds you would get two runs per mould as the coating stops all burning. But, maybe that would be pushing it lol Phone died there so ''Thats all she wrote'' The other 3 are going to be very plain sailing now that everything is proved. Itll probably take me 2-3 evenings to get the other three cast so Ill take some more photos of anything Ive missed along the way now that the pressure is off!! Brian,
Awesome stuff, as always! Errmm...none yet... Where I'm from "I'm after..." means "I want to..." as opposed to the Irish meaning of "I have just..." When I do get round to it, I'll probably just do it the rough way to get it running, then refine from there. Can't be arsed getting too scientific with it...just want to make fire and noise!
