Topic: Okay, it's been more than ten years, Has a fin repair procedure been invented?

[Gonzowerke]

We used to go 'round about this topic back on the Dorje list. I was given a sweet ported head about 15 years ago. Problem is, it came from a race engine that had been laid down, so it was missing finnage on the right hand side. Has anyone come up with a good method of fin repair? A couple of them are broken an inch or more down, so I can't see paying someone way too much money to try and build them up with a TIG welder.

[rebabal]

Paper Mache.

[Jerry Rxman Griffin aka MuthaF'er]

I think it's been mostly talk about JB Weld, TIG, etc. No great solutions. IMO TIG would be the best solution but it's one of those things I can not do for myself so I'd have to pay. We do have a member that does micro aluminum welding on carbs etc. Perhaps?? OR, just pop the ones on the other side and make it look like it's a planned event 

[horror]

Iv'e seen it done with the welding method, but cutting pieces out of sheet to the shape then weld them on.

[754]

Best thing if they are missing.. find a donor head and cut off the ones you need.. and use them. I am sure there aare a fee scragged heads out here in 750 land..

 Where are you at..?

 Probably better to get a fin specialist to put them on than to xperiment on a head you want to save..

[Hannibal Smith]

I just had some fins repaired via TIG, and with some file work are virtually invisible, unless you know where they are and go looking.

Welding is the only current method (that I know of) that I don't have to worry about down the line.

Pretty hard to spot!

[mycb750k6]

My buddy just had his entire top fin replaced on the right side by a welded piece of aluminum. Impossible to tell it was done. I guess the trick is finding someone who is capable of doing it in your area. But the answer is a good TIG welder. This was in LA. I think you'd be wasting your time with JB Weld.

[KB02]

At a trade show, I have seen a new product that works on all non-ferrous metals (aluminum). It uses only the heat of a blow torch and ends up being stronger than the parent metal. I'll have to search to see if I can find it. The guy at the trade show had a cylinder from some bike that had fin repaired with the stuff.


 - Edit -

Found it:

[turboguzzi]

At a trade show, I have seen a new product that works on all non-ferrous metals (aluminum). It uses only the heat of a blow torch and ends up being stronger than the parent metal. I'll have to search to see if I can find it. The guy at the trade show had a cylinder from some bike that had fin repaired with the stuff.


 - Edit -

Found it:

would give this a try, but maybe do a test on an old head first to gain experience....  you could melt whole chunks (of the head) if you are not careful...

http://durafix.co.uk

http://durafix.co.uk/pages.php?&pID=6

[ksmith0034]

You could try HTS-735-II.  I tried it on one of my fins but couldn't get anything more than a globby mess out of it.  I guess I don't have the welder's touch.  Compare it to AlumiWeld as they look to be very similar.  HTS-735-II can be purchased at www.aluminumbrazingrod.com

[mycb750k6]

I found this on HTS-2000 FWIW. Looks like it might be worth a try. Claims to be superior to alumiweld and the rest but that's not surprising. There's videos on it's use.
http://www.aluminumrepair.com/faqs.asp

[mystic_1]

HTS, and Alumiweld seem like quite similar products to me.  I've never tried HTS, seen videos though.  Have tried Alumiweld, here's what I found:

http://forums.sohc4.net/index.php?topic=36600.0

You'll need more than jut a torch to use these products on a cylinder head, large chunks of aluminum wick the heat away from the work zone too quickly.  So, you need to pre-heat the part and work quickly when the part is large like that, or have some other way to keep the item's temp up.

mystic_1

[Hannibal Smith]

I am afraid there is no miracle cure here.
TIG keeps the heat high and local and with shielding gas...................and it works perfectly in capable hands, just look at my repaired cylinder.
You are going to have to bite the bullet and pay a pro to do it if you want it done right. No ifs and or buts...............................IMO.

[754]

I can see where folks would like to do it themselves, however it often looks it..

 I am always amazed when people tell me they think they are going to be able to ace aluminum welding, when most  fulltime welders have a bit of a learning curve getting used to it.

  If you can ace it, you shoulda got into it a lot earlier..

 Sometimes  you may want to clean it up yourself, some welders go a bit overboard on the cleanup..

[Spikeybike]

from one of my build threads :

finished this a couple weeks ago had it on the back burner for awhile,
when i first got this it was all beat up and the bottom fin was broken off


welding cast (alloy especially) almost always just brings up all the contaminants in the metal as you can see by the "not so pretty" welds


then you grind off the poo, and get little tiny pits, from the air pockets (caused by weld contamination)
 

then some more weld (a little prettier this time   )


then ground, sanded, dremeled,polished, painted, polished some more  

if you want it done right ... there is no easy "quick fix"  

and just so you all know , if you use JB (or similar products) and it doesn't work ..all that area with "product" on it is now severely contaminated and can't be welded .. until all that crap is ground off    

[sangyo soichiro]

It's important to remember the main purpose of the fins - to keep the engine cool.  So whatever the fix, if it doesn't conduct heat to the repaired part of the fins, then it's just for show.  So I think welding is probably the best solution.


Nice looking fins Spikey!

[Alan F.]

You'll need more than just a torch to use these products on a cylinder head, large chunks of aluminum wick the heat away from the work zone too quickly.  So, you need to preheat the part and work quickly when the part is large like that, or have some other way to keep the item's temp up.

Exactly! plus you'd likely have to heat the block up to 400*F-500*F to be able to heat the area of the repair sufficiently to use HTS.

So unless you're ready to have a few helpers wave torches over the part and have another helper with an infra-red thermometer making spot checks so someone doesn't melt anything...all while you try to braze a fin back on with HTS...yuck.
Or maybe work the part while it's still sitting hot in an oven.... But welding is probably a better choice.

I've been working with HTS2000 for a few years and I don't think I'd try it, maybe with a top or a bottom fin only...maybe.
-Alan

[Gonzowerke]

So, in a word, my answer is;

NO.