OzVMX Forum
Clubroom => Tech Talk => Topic started by: kdx Geoff on February 25, 2014, 11:08:36 am
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l have a small piece of fin missing and looking for ideas to make it look right. . Making a piece to fit in seems pretty straight forward but having stay in place...... lm going to paint the engine after the repair.
(http://i1297.photobucket.com/albums/ag23/kdxGeoff/IMAG1376_1_zps759e838a.jpg) (http://s1297.photobucket.com/user/kdxGeoff/media/IMAG1376_1_zps759e838a.jpg.html)
Thanks
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I'd just use devcon, & use plastic or something to shape until it hardens then dress it up with a file, coat of gravy all good.
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tig weld a donour peice in ;) then done and dusted all proper like
looks fresh have ya got the missing bit off the jig saw?
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Not a big piece missing from what I can see, build it up with a few beads on the tig & file it back to shape
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Not a big piece missing from what I can see, build it up with a few beads on the tig & file it back to shape
Yep I would go with that ;) ;D
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Thanks blokes
option 1 seems the simple fix :)
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Devcon is probably your simple fix, personally I would weld it but then I'm biased.
The missing piece is irrelevant as it is much easier to fill the cavity than try to hold a small piece in place and get penetration both sides.
I would just pitch the broken piece when you weren't looking ;D and build it up with weld.
Down side is you would need to take the barrel off for welding and for the perfect finish you would want to blast with a course garnet to get the cast texture back before painting as the patch would be smooth after sanding back.
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Devcon is probably your simple fix, personally I would weld it but then I'm biased.
The missing piece is irrelevant as it is much easier to fill the cavity than try to hold a small piece in place and get penetration both sides.
I would just pitch the broken piece when you weren't looking ;D and build it up with weld.
Down side is you would need to take the barrel off for welding and for the perfect finish you would want to blast with a course garnet to get the cast texture back before painting as the patch would be smooth after sanding back.
Agree ;) the best way is not allways the easiest
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Hi Geoff, sorry I should have read this earlier. YOu could shape your piece and then some sort of metal glue will work fine. Some years and about 5000 miles back in used adhesive to repair the casting on a Z900 cyl head, tach drive part of the casting was broken off and still bolted to the cable, I just scrubbed it all with white spirits, mixed the adhesive up and put it back on, its still there with the cable running through it and bolted to it, your fin piece will stay for ever.
Just find a damaged barrel of similar metal and remove a piece so looks same, file to shape wack it on my friend. Easy. No load on it at all.
Let me know if you want me to chase up the brand of adhesive, I borrowed it from my local mc shop, Mick Dyers in Penrith, good bloke with a LOT of experience.
Kt.
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just find a damaged barrel........ ???
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just find a damaged barrel........ ???
He's in luck, he already has one ;D
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GMC,hehehe,I was thinking the very same thing.
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whats worse than a broken fin?
A bruised pol
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you cant get in without a tie...bugger ive bought a Cambodian instead
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just find a damaged barrel........ ???
He's in luck, he already has one ;D
kT.
In fact I reckon he has SEVERAL!!!
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Took me a while to find where I had filed this ::)
This is not me but something I found a while ago, it's someone repairing a YZ465 barrel. Thought it might be handy.
This first photo shows one of several broken fins to be repaired.
(http://i388.photobucket.com/albums/oo330/bishboy/Miscellaneous/finrepair1_zpsb13854c9.png) (http://s388.photobucket.com/user/bishboy/media/Miscellaneous/finrepair1_zpsb13854c9.png.html)
You can see I have already removed most of the paint and have cleaned and sanded back the affected areas. The plan was to weld up the fin by making multiple passes with the tig welder rather than weld on a fin from a donor cylinder.
Next the cylinder was pre-heated in an oven. Aluminium is a very good conductor and will quickly draw heat away from the weld and into the surrounding mass. This can affect penetration and the time and energy required to puddle the aluminium at the weld site.
A concern was the rod compatibility. But good results were obtained with a general purpose aluminium rod I already on hand.
This next photo shows the first run of aluminium bead made with the tig welder.
(http://i388.photobucket.com/albums/oo330/bishboy/Miscellaneous/finrepair2_zps5198f001.png) (http://s388.photobucket.com/user/bishboy/media/Miscellaneous/finrepair2_zps5198f001.png.html)
After 3 passes it looked like this,
(http://i388.photobucket.com/albums/oo330/bishboy/Miscellaneous/finrepair3_zps375dc26e.png) (http://s388.photobucket.com/user/bishboy/media/Miscellaneous/finrepair3_zps375dc26e.png.html)
After several more passes, there is more than enough material to shape the repaired fin.
(http://i388.photobucket.com/albums/oo330/bishboy/Miscellaneous/finrepair4_zps0e7883ce.png) (http://s388.photobucket.com/user/bishboy/media/Miscellaneous/finrepair4_zps0e7883ce.png.html)
Next is the repaired fin after a little shaping with a grinder and hand file. There is still some work to do but I was pleased with the weldability of the cylinder and the overall result (after a little more work).
(http://i388.photobucket.com/albums/oo330/bishboy/Miscellaneous/finrepair5_zps4dc1122f.png) (http://s388.photobucket.com/user/bishboy/media/Miscellaneous/finrepair5_zps4dc1122f.png.html)
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That's looks like a good repair. I'll look at welding when l need to take the barrel off.
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Thanks to the swingarm bolt it took me a while to get back to this.
I'd just use devcon, & use plastic or something to shape until it hardens then dress it up with a file, coat of gravy all good.
Cleaned the break with brake clean and blew it off. Attached the formwork with ultra blue and let it set for a couple of hours.
(http://i1297.photobucket.com/albums/ag23/kdxGeoff/IMAG1697_zps81a1674e.jpg) (http://s1297.photobucket.com/user/kdxGeoff/media/IMAG1697_zps81a1674e.jpg.html)
The Devcon is quite viscous but still flows so the fin had to be level and then l had to resist the temptation to touch it for 24 hours :o
(http://i1297.photobucket.com/albums/ag23/kdxGeoff/IMAG1698_zpsc2e64434.jpg) (http://s1297.photobucket.com/user/kdxGeoff/media/IMAG1698_zpsc2e64434.jpg.html)
Removed the formwork and gently filed the patch to the fin profile.
(http://i1297.photobucket.com/albums/ag23/kdxGeoff/IMAG1701_zpsbf130410.jpg) (http://s1297.photobucket.com/user/kdxGeoff/media/IMAG1701_zpsbf130410.jpg.html)
Apply paint.
l gave the repaired fin a quick rub with steel wool and painted it just to see how obvious the repair is.
(http://i1297.photobucket.com/albums/ag23/kdxGeoff/IMAG1707_zps43718430.jpg) (http://s1297.photobucket.com/user/kdxGeoff/media/IMAG1707_zps43718430.jpg.html)
If l had the barrel off l might go down the welding path but we'll see how durable this repair is. :)
Thanks for your input oldstuff :) I've blocked out some of the other comments ;D
Cheers
Geoff