Hole in a brass casting

[Puzzledprofessor]

Help, please. I was sanding a brass trigger guard and discovered a bubble in the casting. Any tips on filling it. Could I fill it with solder?

[rich pierce]

Many originals have casting flaws but there are several approaches that can work for you.  First, you can try to peen it closed and it will be less obvious.  Second, you could drill it through and make a brass rivet to fill it in.  There is a yellow solder around but I forget where it is from. Regular solder will show.

[Mike Brooks]

I have always used solder, and it will be visible. the above post may be better advice.

[Curtis]

I have used this product with excellent results:
https://www.riogrande.com/Product/brass-wire-solder-20-ga/132201

Curtis

[moleeyes36]

I have used this product with excellent results:
https://www.riogrande.com/Product/brass-wire-solder-20-ga/132201

Curtis

Curtis,

I've seen this solder on the Rio Grande site in the past and have considered getting some.  What flux do you use with it?

Mole Eyes

[EC121]

If you read the reviews for the solder, they used My-T- Flux with good results.

[jerrywh]

 How big and how deep is the hole?  The solder sold by Rio Grande is the same as silvaloy 45.
 It is 45 % silver the rest is copper and zinc I believe. It can be bought on Ebay under the name silvaloy45. I have used it several times and it maches pretty well but not exact. If the hole is small it is much easier to fill with a rivet or an inlay of 360 brass or a piece of regular brazing rod. If you have never done a brass inlay you should learn how. It is not as hard as brazing. The flux for silvaloy is borax or boric acid.

[Curtis]

MoleEyes,

I use the MyTFlux.  That flux has worked well for me also on regular silver solder, brass braising, copper braising, etc.  I have also used it in conjunction with borax for braising.
https://www.riogrande.com/Product/my-t-flux-1-pint/504006

Curtis

[bama]

It depends on you and what you want. I have seen many original guns that had casting flaws that were left as is, if it was small that is what I would do, if it is large then any of the above comments will work.

[Mark Elliott]

I have used this product with excellent results:
https://www.riogrande.com/Product/brass-wire-solder-20-ga/132201

Curtis

I have used this a couple of times and in one case (a repair) the color match was good, and in the other (filling a small void) , not so good.   I think, in the future I would follow the advise to leave small flaws as they are.   

[Puzzledprofessor]

Thanks to all for the great info and advice. The hole is on the large size, about the size of 3/4 of the fingernail on your pinky. I don't think I will mind a color diference with the repair so I think I will give soldering a try. I am really enjoying building my first flintlock and I looks like this fourm is going to be a great resource. Thanks again for the quick and informative responses.

[JLBSparks]

A competent welding shop could probably braze a patch into your void. If the triggerguard is nearly fitted/finished it may be better than starting with a new casting.

     -Joe

               Amateur gunbuilder. Professional fabricator.

[little joe]

I have did several using silver solder and they are vary hard to see when finished.

[M. E. Pering]

Greetings to the group!I have lurked around here for a couple years, but finally signed up today, and thought I could give a bit of insight into this problem. 
The substance I have used in the past is a product by Radnor (Harris) called Safety-Silv 45.  It is an alloy of 45% silver, 30% copper and 25% Zinc.  It does have a yellowish color when finished, but it may not be a true match for brass, since I am almost certain it would tarnish at a different rate, considering the silver content.
One option might be, however, is to cut an inlay to fit the hole from brass, and to solder that in with this stuff.  A very competent welder could probably also do the job with an acetelyne or carbon-arch torch, but that would probably cost you more than the guard is worth.
Personally, I would get another TG and save that one for later, to be melted down as scrap.  Casting your own brass is a rewarding endeavor, and that is how I would deal with it.  Good luck.

Matt

[moleeyes36]

Thanks to all for the information on the correct flux to use.

Mole Eyes