Sikaflex 11fc and splicing?

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heath loxton
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Sikaflex 11fc and splicing?

Post by heath loxton »

Hi,
I have ordered some sikaflex 11fc as I have heard it is good for splicing bottles together if you do not have access to pl premium, I don't as I live in Australia. I was wondering;

1) what is the MAXIMUM psi that it can safely handle?
2) what are other peoples experiences with glue and splicing?

Cheers, Heath Loxton :D
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Jamie5335
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Re: Sikaflex 11fc and splicing?

Post by Jamie5335 »

Hello Heath,

Air Command Rockets have used Sikaflex and I would recommend their website in general for water rocket info.

Here is a link to some burst test they have done using Sikaflex, PL Premium and FIbreglass.


Scrolling through it you see that Sikaflex bursts at around 110 PSI, and the average water rocket launching pressure is 120psi.

This doesn't make it a great glue to withstand the strength of the forces I am afraid. However it is an excellent PET plastic sealer and can be used in the join for splicing bottles to help seal them as usually strength Polyurethane glues bubble and leak, yet withstand the pressure.

Personally, I use Air commands Asymmetric Splicing (see link below), using a uk version of Sikaflex for the seal and then a standard runny wood Polyurethane glue as the strengthener and little cornflour to thicken it.- on its own it leaks badly, yet with the sealer in it, it holds the pressure and does not leak.


Hope that helps, I take no credit for Air Command's work- they are the kings of Water Rocketry!

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Team Seneca
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Re: Sikaflex 11fc and splicing?

Post by Team Seneca »

Jamie5335 wrote:Hope that helps, I take no credit for Air Command's work- they are the kings of scouring the internet for ideas to repost and take credit for!
I fixed it for you. 8)
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heath loxton
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Re: Sikaflex 11fc and splicing?

Post by heath loxton »

I plan on launching at 90psi!

cheers, heath Loxton :)
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U.S. Water Rockets1
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Re: Sikaflex 11fc and splicing?

Post by U.S. Water Rockets1 »

heath loxton wrote:Hi,
I have ordered some sikaflex 11fc as I have heard it is good for splicing bottles together if you do not have access to pl premium, I don't as I live in Australia. I was wondering;

1) what is the MAXIMUM psi that it can safely handle?
2) what are other peoples experiences with glue and splicing?

Cheers, Heath Loxton :D
We don't have that brand here in the U.S. so we can't give you exact numbers. However, it looks like it is a white RTV silicone adhesive. If it is, then it probably would not make a strong joint. If you used this as your splice glue, you would probably have to make a really large overlap to get any strength and would also probably have to add extra layers of PET over the top of the joint to make it as strong as a PL splice.
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jerm
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Re: Sikaflex 11fc and splicing?

Post by jerm »

Hi,
I use FC11 on all me joints and fins and it is fine. I have a 30mm overlap on the splice and have had only 1 splice fail. I have gone to 100psi for launch. PL premium is the best but for 90psi the FC11 is fine. Sand the joint very well with about 120 sand paper on both surfaces and apply the glue to both surfaces and join the bottles together with a slight twist at the end for the best joint. The FC11 is a very good sealant, let the glue dry for 4 days or a week is good and then test.
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Re: Sikaflex 11fc and splicing?

Post by Team Seneca »

jerm wrote:Hi,
I use FC11 on all me joints and fins and it is fine. I have a 30mm overlap on the splice and have had only 1 splice fail. I have gone to 100psi for launch. PL premium is the best but for 90psi the FC11 is fine. Sand the joint very well with about 120 sand paper on both surfaces and apply the glue to both surfaces and join the bottles together with a slight twist at the end for the best joint. The FC11 is a very good sealant, let the glue dry for 4 days or a week is good and then test.
DY Water Rockets.
Is FC11 a silicone based glue?
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Spaceman Spiff
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Re: Sikaflex 11fc and splicing?

Post by Spaceman Spiff »

Team Seneca wrote:Is FC11 a silicone based glue?
I read some where that it was a PU based glue, but what I see in various videos and tutorials from people like George and Batkiter is something that looks like plain old white RTV sealant. I get the feeling that the Sikaflex is used simply as a rubbery gasket and the hoop of PETG glued on with PLP is the actual structural bond. I thought I remember reading that somewhere.
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Re: Sikaflex 11fc and splicing?

Post by Water Rocket Expert »

Silicone Rubber Cement J4 Cement also works well for splicing at low pressures (130) psi.
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