Hi Daniel, Yes, that is exactly why we like to use the technique because it allows water and air to pass through easily. We make the tornado couplings out of 3/4" BSP sockets used for irrigation plumbing. We have to re-thread them on the lathe to fit the bottle type thread. We also machine in an o-ring seat to seal them up. You can buy commercial tornado couplings for a couple of dollars on line.
Thanks for the answer George, I must study more that type of coupling, now I got the glue and I will serch for the bottles :) I make some progress in the water rocket with boosters, I got the 50% of the main stage finished. I got a 7mm nozzle, three 9mm metal nozzle for the boosters, this boosters will got 3l of capacity each one (I will join two 1.5l bottles in each one with 9mm robison coupling) I got a 6mm aluminium tube for the retention tubes and the nozzle sits for the boosters.
Hi Daniel, You can use the technique with any sized bottles as long as they have straight sides. You may be able to find two 1.5 L bottles from different manufacturers that fit inside one another. You then would not need to shrink the sleeve.
@luisal1895 The best bottles are ones with straight sides. You just need to go down to your local supermarket and see what they carry. You may need to check several stores for different brands. Make sure you get bottles that were meant to carry soda / soft drinks, as ones that only carry water aren't designed for pressure.
@THISNAMEOWNS No, a hole in the center will make the parachute a little more stable, but come down quicker. Make sure you fold the parachute properly and only wind the string around it once or twice to make it open sooner. If you are deploying using a timer, set it to deploy prior to apogee so that by the time the parachute is fully open, the rocket has reached apogee.
I look forward to seeing your 2L bottle splicing tutorial. I am drinking soda like crazy and have a large supply of 2L bottles waiting for me to start work. My initial goal is very modest ... get onboard flight video. Later, I would like to go for altitude.
@DotCmaker01 Yes, polyurethane glues will often bubble up. How much they do depends on the glue and how humid it is when curing. As long as it is holding the splice and not leaking then there shouldn't be an issue.
We have tried VISE glue which is polyurethane based, but is quite runny. We added a fine powder and made a thicker paste which worked quite well. It held up to around 180psi. Look for polyurethane glues and give them a try.
Thanks alot! This is really helpful! I'm just wondering though, I have this home-bond "super strength epoxy adhesive", and I was wondering if that would work as well to attach the bottles? My friend used some hot glue on his rocket and he thinks it's going to hold up under pressure. Lol.
You can try the epoxy. Someone has mentioned before that it can work. Generally though you want to use a polyurethane glue that has a flexible bond. The bottles will stretch when pressurised and rigid bond glues like epoxy can crack and break the seal.
Thanks. We get our PL from the states. On my last visit to the states in December I brought back 15 tubes of the stuff. Hopefully that will last until the next visit. :) If you have friends in the US they can send you some. A flat rate box costing US$37 can fit 11 tubes. Each tubes costs in the order of US$5. Perhaps you can share shipping costs with some friends who also want some PL.
Hi Chris, I'm not sure which glues are sold in Europe, but you want to look for Polyurethane based glues that end up having a flexible bond. Make sure you also lightly sand the surfaces for better adhesion.
@deskmations It may be possible, but quite hard to control the amount of stretch you would get. The better option is to use hot water to shrink one of the bottles a little. You just need to briefly dip the end of the bottle in water that is about 72 degrees C. and it will shrink a couple of mm.
@josephdupont You can splice as many as you like this way. The splice turns out to be stronger than the bottles. We now wrap them with fiberglass and they hold 300psi+
You can shrink the bottles slightly but submerging them in hot water (~72 degrees C) up to the level you want to insert them in the other bottle. Submerge them only for a couple of seconds and then see if they fit. If not repeat it for a few more seconds. You can then curl the ends as normal. If you would like more info send me a PM there isn't enough room here.
You could try the same diameter bottle and cut the sleeve down its length and then glue another cut sleeve over the top of that with the cut on the other side. Or you could try shrinking the bottles a little and then use an unshrunk sleeve.
Depends on the type of glue the Liquid nails is. I believe there are different formulations. If it is polyurethane based it may work, but I think I remember others trying it, and they didn't have much luck with it.
This video is great very well done. I have tried this in the past with varying success but this has inspired me to give it another go. One question where do you source the PL Premium glue from haven't been able to find it down here in Victoria. Cheers and great vid
Hi George, I think that this type of water rocket construction gives a lot of more performance to the rocket because the air and the water can get out easyly. I saw in your web site that you use the tornado coupling for this kind of rockets. Where can I find the black piece of plastic for make the coupling? Thanks for the video, is great.
There is a link on our website (can't post URL here) just under our Robinson coupling video, to another site that describes how to make Robinson couplings the traditional way with a hollow threaded lamp rod. Those instructions are a much clearer.
You can use virtually any heat source such as heat gun, in front of heater, over the stove or BBQ. We used a blow torch because we didn't have a heat gun at the time. You only need to heat the plastic to around 80-90C. You could potentially use hot water but the risks of a pressurised bottle going POP inside a tub of hot water is too dangerous. The foam we use is simply 1-2% of kids bubble bath dissolved in the water.
@taneorox We have tried epoxy, but it just doesn't stick as well to PET as polyurethane glue does. The glue needs to be a little flexible aswell as the bottles stretch under pressure.
@DotCmaker01 Other glues will work, but perhaps not as well. You want to look for polyurethane based glues, ones that are not too runny. Glues like epoxy don't stick well to PET plastic.
Hi Daniel, Sounds like you are progressing well with the rocket! :) Are you using brass nozzles on the boosters? You may want to consider using plastic ones if you can. That will reduce the weight of the rocket. I'm looking forward to seeing your rocket fly! :)
@MrTomcarnahan Hi Tom, We are working on a 2L bottle splicing tutorial at the moment that only uses the same size bottles. I will post it in the coming weeks. Whether you go for FTC or PET bottles will depend on what you are trying to achieve. FTC has low drag so the rockets can go fast, but have a small volume so are not suitable for lifting heavy payloads or as lower stages on multistage rockets.
Clear silicone sealant will not work. It just does not have the bond strength required. There is about half a tonne of force acting to pull the two bottles apart when they are fully pressurised.
You just need a heat source. You could do it above the kitchen stove, or BBQ, or in front of a heater if it is hot enough. You just want to be careful not to burn a hole in it since there is a little pressure inside the bottle.
thanks, the video was great, the only problem is, on a simpler rocket ( or any rocket ) what do you use as the cap? where air can go in, but water cant come out.. do you know what i mean? please help...... thanks
You can make Robinson couplings easily the same way as Bill Robinson made them initially with hollow threaded lamp rod and a couple of nuts and washers. Do a Google search for ' "Robinson" Coupling' and it should be one of the first on the list. (can't post url here) There is also a link to it on our main website under Construction / Robinson coupling.
i make the splices with polueurethane based glue it works well, but the glue turns into very hard foam. is this normal? or should i look for other glue?
Certainly if you burn it, unpleasant gases can be given off. We only ever heat the plastic, not burn it so the potential to liberate gases is minimal. All the heating procedures in the tutorial only need to be 80-90 Degrees C. Earlier comment about wearing gloves when handling PL Premium is highly recommended.
Hi George, I got a problem because here, the only bottles that I find are of 1, 1.5, 2 and 2.5l , I find one of 1.25 of CocaCola, but it is not straight. Could I do this with only 1.5l bottles?
hey there... i got problem here.. i got 2 bottle of 1.25L..and 1 bottle of 1.5L.. both 1.25 n 1.5 has same diameter but different length.. should i shrink the 1.5 little bit n connect to 1.25 botle? any suggestion?
@Abalancedproduction This technique will work for various kinds of straight walled bottles. You just need a slightly larger bottle for the sleeve than what you are splicing together. We are working on a new tutorial that lets you use the same bottles for everything.
i have 3 same bottles of 2.25L and i have problems in sticking both of them together becuz i cant put the bottle over the other 2 bottles im sticking plz help
hey well i failed at school cuz after i stick it so hardly the two bottles and the sleeve but when i was pumping air it broke in two two bottles again well still thank you and peace.
1) You really should wear disposable gloves when using PL premium. Yeah you can be super careful but that stuff is nasty when you get it on your skin and accidents do happen. 2) Where I live Coke 2L bottles (and other beverages from that bottler) and Pepsi 2L bottles are of slightly different diameters such that one naturally forms a sleeve for the other.
Hi Daniel,
Yes, that is exactly why we like to use the technique because it allows water and air to pass through easily.
We make the tornado couplings out of 3/4" BSP sockets used for irrigation plumbing. We have to re-thread them on the lathe to fit the bottle type thread. We also machine in an o-ring seat to seal them up. You can buy commercial tornado couplings for a couple of dollars on line.
Thanks for the answer George,
I must study more that type of coupling, now I got the glue and I will serch for the bottles :)
I make some progress in the water rocket with boosters, I got the 50% of the main stage finished. I got a 7mm nozzle, three 9mm metal nozzle for the boosters, this boosters will got 3l of capacity each one (I will join two 1.5l bottles in each one with 9mm robison coupling)
I got a 6mm aluminium tube for the retention tubes and the nozzle sits for the boosters.
dude this song is great. Excellent tutorial
amazing tutorial. I've been looking for a good set of instructions on how to do this for a while.
Hi Daniel,
You can use the technique with any sized bottles as long as they have straight sides. You may be able to find two 1.5 L bottles from different manufacturers that fit inside one another. You then would not need to shrink the sleeve.
@luisal1895 The best bottles are ones with straight sides. You just need to go down to your local supermarket and see what they carry. You may need to check several stores for different brands. Make sure you get bottles that were meant to carry soda / soft drinks, as ones that only carry water aren't designed for pressure.
@THISNAMEOWNS No, a hole in the center will make the parachute a little more stable, but come down quicker. Make sure you fold the parachute properly and only wind the string around it once or twice to make it open sooner. If you are deploying using a timer, set it to deploy prior to apogee so that by the time the parachute is fully open, the rocket has reached apogee.
I look forward to seeing your 2L bottle splicing tutorial. I am drinking soda like crazy and have a large supply of 2L bottles waiting for me to start work.
My initial goal is very modest ... get onboard flight video. Later, I would like to go for altitude.
Nicely made informative tutorial! Thumbs up!
Thumbs up for the simple fact that you used Bjork as a musical background.
@DotCmaker01 Yes, polyurethane glues will often bubble up. How much they do depends on the glue and how humid it is when curing. As long as it is holding the splice and not leaking then there shouldn't be an issue.
We have tried VISE glue which is polyurethane based, but is quite runny. We added a fine powder and made a thicker paste which worked quite well. It held up to around 180psi. Look for polyurethane glues and give them a try.
Thank you very much, that's information which will save me some heartache :)
Thanks alot! This is really helpful!
I'm just wondering though, I have this home-bond "super strength epoxy adhesive", and I was wondering if that would work as well to attach the bottles?
My friend used some hot glue on his rocket and he thinks it's going to hold up under pressure. Lol.
You can try the epoxy. Someone has mentioned before that it can work. Generally though you want to use a polyurethane glue that has a flexible bond. The bottles will stretch when pressurised and rigid bond glues like epoxy can crack and break the seal.
Thanks. We get our PL from the states. On my last visit to the states in December I brought back 15 tubes of the stuff. Hopefully that will last until the next visit. :) If you have friends in the US they can send you some. A flat rate box costing US$37 can fit 11 tubes. Each tubes costs in the order of US$5. Perhaps you can share shipping costs with some friends who also want some PL.
Hi Chris, I'm not sure which glues are sold in Europe, but you want to look for Polyurethane based glues that end up having a flexible bond. Make sure you also lightly sand the surfaces for better adhesion.
@deskmations It may be possible, but quite hard to control the amount of stretch you would get. The better option is to use hot water to shrink one of the bottles a little. You just need to briefly dip the end of the bottle in water that is about 72 degrees C. and it will shrink a couple of mm.
@josephdupont You can splice as many as you like this way. The splice turns out to be stronger than the bottles. We now wrap them with fiberglass and they hold 300psi+
@TheTigertruck 120psi should be good if you use PL premium. Other glues may not be as strong. Always do a hydro-test first to make sure.
You can shrink the bottles slightly but submerging them in hot water (~72 degrees C) up to the level you want to insert them in the other bottle. Submerge them only for a couple of seconds and then see if they fit. If not repeat it for a few more seconds. You can then curl the ends as normal. If you would like more info send me a PM there isn't enough room here.
You could try the same diameter bottle and cut the sleeve down its length and then glue another cut sleeve over the top of that with the cut on the other side. Or you could try shrinking the bottles a little and then use an unshrunk sleeve.
Depends on the type of glue the Liquid nails is. I believe there are different formulations. If it is polyurethane based it may work, but I think I remember others trying it, and they didn't have much luck with it.
Yes it does, but you need to make sure you have a bigger sleeve. Here we have 2.25L bottles as well so we use the sleeve from those.
This video is great very well done. I have tried this in the past with varying success but this has inspired me to give it another go. One question where do you source the PL Premium glue from haven't been able to find it down here in Victoria. Cheers and great vid
Hi George,
I think that this type of water rocket construction gives a lot of more performance to the rocket because the air and the water can get out easyly.
I saw in your web site that you use the tornado coupling for this kind of rockets. Where can I find the black piece of plastic for make the coupling?
Thanks for the video, is great.
There is a link on our website (can't post URL here) just under our Robinson coupling video, to another site that describes how to make Robinson couplings the traditional way with a hollow threaded lamp rod. Those instructions are a much clearer.
@twolate2l00k No. Your best bet is to look for polyurethane glues. They stick fairly well to PET.
You can use virtually any heat source such as heat gun, in front of heater, over the stove or BBQ. We used a blow torch because we didn't have a heat gun at the time. You only need to heat the plastic to around 80-90C. You could potentially use hot water but the risks of a pressurised bottle going POP inside a tub of hot water is too dangerous.
The foam we use is simply 1-2% of kids bubble bath dissolved in the water.
@taneorox We have tried epoxy, but it just doesn't stick as well to PET as polyurethane glue does. The glue needs to be a little flexible aswell as the bottles stretch under pressure.
I have no experience with that glue. Would be interesting to hear what your experiences are with it, if you choose to give it a go.
@DotCmaker01 Other glues will work, but perhaps not as well. You want to look for polyurethane based glues, ones that are not too runny. Glues like epoxy don't stick well to PET plastic.
Hi Daniel,
Sounds like you are progressing well with the rocket! :) Are you using brass nozzles on the boosters? You may want to consider using plastic ones if you can. That will reduce the weight of the rocket.
I'm looking forward to seeing your rocket fly! :)
@MrTomcarnahan Hi Tom, We are working on a 2L bottle splicing tutorial at the moment that only uses the same size bottles. I will post it in the coming weeks. Whether you go for FTC or PET bottles will depend on what you are trying to achieve. FTC has low drag so the rockets can go fast, but have a small volume so are not suitable for lifting heavy payloads or as lower stages on multistage rockets.
@ekitoo2 Look for polyurethane glues as they stick the best to PET. Though PL premium is usually 2-3 times stronger than other PU glues.
Clear silicone sealant will not work. It just does not have the bond strength required. There is about half a tonne of force acting to pull the two bottles apart when they are fully pressurised.
The glue is polyurethane based. If you can't find PL look for a similar PU based glue that cures with a flexible bond.
Thanks. No I haven't seen Scott's video. Do you have a link to it? Is it available on the net?
You just need a heat source. You could do it above the kitchen stove, or BBQ, or in front of a heater if it is hot enough. You just want to be careful not to burn a hole in it since there is a little pressure inside the bottle.
thanks, the video was great, the only problem is, on a simpler rocket ( or any rocket ) what do you use as the cap? where air can go in, but water cant come out.. do you know what i mean? please help...... thanks
@fatpeople249er Thanks for the update. The launcher looks pretty good, have you launched any rockets with it?
You can make Robinson couplings easily the same way as Bill Robinson made them initially with hollow threaded lamp rod and a couple of nuts and washers. Do a Google search for ' "Robinson" Coupling' and it should be one of the first on the list. (can't post url here) There is also a link to it on our main website under Construction / Robinson coupling.
is there anything else I can use to shrink the sleeve other than a blow torch?and what kind of foam do you use for your rocket?
As far as I know, it is only available in the US, but you can order it online and have it delivered.
I actually lol'd at the frying pan xD
@TheTigertruck Nope. It just is not strong enough. You really need to use a polyurethane based glue.
Thanks allot for the info
i make the splices with polueurethane based glue it works well, but the glue turns into very hard foam. is this normal? or should i look for other glue?
Certainly if you burn it, unpleasant gases can be given off. We only ever heat the plastic, not burn it so the potential to liberate gases is minimal. All the heating procedures in the tutorial only need to be 80-90 Degrees C.
Earlier comment about wearing gloves when handling PL Premium is highly recommended.
Respond to this video...
but can i use hot glue if i really cant find any pl premium or polyurethane glues
Nice Bjork!
Hi George,
I got a problem because here, the only bottles that I find are of 1, 1.5, 2 and 2.5l , I find one of 1.25 of CocaCola, but it is not straight.
Could I do this with only 1.5l bottles?
Congratulations. Excellent! Thanks.
Félicitations. Excellent! Merci.
Glückwünsche. Ausgezeichnet! Danke.
Felicitaciones. Excelente! Gracias.
hey there...
i got problem here..
i got 2 bottle of 1.25L..and 1 bottle of 1.5L..
both 1.25 n 1.5 has same diameter but different length..
should i shrink the 1.5 little bit n connect to 1.25 botle?
any suggestion?
And I got the wood base, the release head and the guide rail :).
@josephdupont No we haven't. Do you have any experience with it?
Hi, what kind of bottles do you recommend to use? Coca cola are not the best and I don't know of a good bottle, can you recommend me one?
are there any other glues that work with the splice?
in the NL the don't seem to sell PL Premium glue........
does this work the same way for two 2 liter bottles?
@Abalancedproduction This technique will work for various kinds of straight walled bottles. You just need a slightly larger bottle for the sleeve than what you are splicing together. We are working on a new tutorial that lets you use the same bottles for everything.
can i use PVC glue or HOT GLUE becouse i cant find any pl premium glue
I love Björk
okej, here is my problem!! in sweden we only have PL 200, PL 400, PL 600. Not PL Premium! can i order it from the us? can you send me a webpage?
@Abalancedproduction Yup. That should be warm enough.
Has anyone tested clear silicone sealant in place of the glue for splicing the bottles?
i have 3 same bottles of 2.25L and i have problems in sticking both of them together becuz i cant put the bottle over the other 2 bottles im sticking plz help
can i use PVC glue or HOT GLUE
@gk123434534 no but can i use hot glue cause i really cant find any hot glue
@maxiiimusIII
only 50ft?
my rocket flys with a 1l tank 90ft :/
@gk123434534 thanks a lot. i've made a spliced pair from 2 1.5L pet bottles. they seem to work with the sleeve so i hope it works under pressure ^,^
i used 2 - 2L bottle of coke, 3 - 1.5 bottles, some adhessives and helium gas,.
i wonder how it came to fly around 50ft above! :))
If you visit our main website, there are detailed instructions on how to build simpler water rockets.
Whats actually the glue?
@twolate2l00k Well, I won't stop you from using hot glue. But be aware that it won't hold pressure very well.
@ekitoo2 can i use PVC glue or HOT GLUE
nope
PL Premium. It is a polyurethane based glue that has excellent adhesion to PET plastic.
hey well i failed at school cuz after i stick it so hardly the two bottles and the sleeve but when i was pumping air it broke in two two bottles again well still thank you and peace.
1) You really should wear disposable gloves when using PL premium. Yeah you can be super careful but that stuff is nasty when you get it on your skin and accidents do happen.
2) Where I live Coke 2L bottles (and other beverages from that bottler) and Pepsi 2L bottles are of slightly different diameters such that one naturally forms a sleeve for the other.
u should make a video in HD
Well only 1.5 liter bottles but I'm trying to make a 3 stage rocket
I hate how there is always music in tutorials. I would prefer silence over a song mismatched to the content.
The tutorial itself is excellent however.
why are you makeing rocket science out of glueing two bottle-..... waaaaait a secon,
nice,but cooking/burning plastic is really bad for your health.
i think it's poisonous
my ears are bleeding!!! but over all good video
too hard
Hey gorge I made a new launcher check it out
The song is terible. Please, stop it.