Casting defect how best to repair it?

[GreenTwin]

I am not sure about irreplaceable.
Rare perhaps.

I think they could be done with resin-bound sand with a ceramic mold wash.
The water cores would be tricky, depending on exactly what they look like.

How long is that casting?
A larger casting is an easier casting, in my opinion.

It would be much easier if someone had a 3D model of it.
That would greatly simplify making the coreboxes.

If someone originally cast it, then someone else can cast it again.

.

 

[LeRhone]

Hi Lioyd.
I am also making the Merlin where are you?
Allan

 

[Charles Lamont]

Depending on the size of the hole, rather than just filling it with JB-Weld, I think I might drill and tap the hole and then screw in an aluminium plug with either JB-Weld or Loctite to fix and seal it. Once cured, if the plug encroaches on existing features they may then need rectification.

 

[L98fiero]

The reason many companies at least the smaller ones refuse to ship outside the U.S is due to the taxes and fees levied against American products that must be paid by the shipper and the additional time to keep the necessary records just to get it through customs. Nothing to do with xenophobia.

That may be the reason for some companies but my understanding for M-C is that they had a case brought against them by US authorities that involved shipping across borders involving taxes or maybe some other restrictions but it caused them issues they didn't want to have to deal with, including a big fine. That stopped the cross border shipping except to registered businesses, educational institutions and pre-existing customers.

That may not be exactly correct, but that's what I was told.

 

[Lloyd W]

Hi Lioyd.
I am also making the Merlin where are you?
Allan

Hi Allan,
I'm in central eastern France, near Geneva close to the Swiss border.
So I guess we are about as far away as one can get!!
Nevertheless, it's good to hear from you, from someone else making the merlin.
Are you working with Richard Maheu's castings and drawings?
How far have you progressed?

 

[peterl95124]

I am not sure about irreplaceable.
Rare perhaps.

If someone originally cast it, then someone else can cast it again.

look at what happened to for example Paul Breisch castings, or
Shelf Pet Models castings, or the Replica Engines Aurora, once the
person doing them passes away or gets out of the business those
patterns seems to disappear forever and no one ever makes new ones.
so while it is theoretically possible to reconstruct, it seems that it has never
actually happened. that's what I'm trying to say when I say irreplaceable.

this is why I once urged people to consider setting up a museum where
old casting patterns could be saved, and at least digitized, for posterity,
and modelers should specify in their wills that that's where their patterns
should end up when they are gone.

 

[Lloyd W]

Many many thanks to all of you that have taken the time here to offer your advice. I really appreciate all your help.

The casting defect is of a pin hole size but will certainly cause a coolant leak from the water jacket.
The defect is at the end of the casting where heat distortion would perhaps be less, however a good bit of the machining is done and I don't want to apply heat for aluminium soldering where I can't measure or assess what the resulting distortion might be.
Also I can't reliably assess the remaining aluminium thickness around the pin hole so soldering could potentially cause (much) more harm than good and its not a skill I really master.
The consensus for me goes towards an epoxy adhesive and probably I will use Devcon F which is loaded with aluminium and will hopefully not corrode inside the water jacket.
My luck is that the defect location means I can get access to it to apply the adhesive from the inside (coolant side) so in a sense any pressure inside the water jacket should help.

If the epoxy fails I could as suggested here then explore a laser welding solution.

 

[GreenTwin]

patterns seems to disappear forever and no one ever makes new ones

Yes, I keep seeing this happen over and over.
Very sad situation.
I think the best chance for keeping some of these old designs is to get them into 3D, and then spread those 3D models around the world, so that at least someone has a chance of 3D printing patterns, and recreating these engines.

Another option is to scan an existing part, and then pull that into a 3D model, scale it up a bit for shrinkage, and then 3D print a pattern.
Not sure about the copyright aspects of scanning objects.

I am going to recreate the patterns for a Ball Hopper Monitor, and a Frisco Standard, and I have most of that 3D modeling work done.
I already have created 3D printed patterns for a Dake.
I also have a 3D model for an Olds, a Galloway, and a few others, so I hope to get some of those engine castings back into circulation again some day.

(sorrry about the thread off-topic)

.

 

[peterl95124]

If the epoxy fails I could as suggested here then explore a laser welding solution.

Lloyd, I've been using epoxy "additive machining" for years to recover from machining
mistakes (who me, make mistakes, not possible !) and never once had any epoxy failures !