Hydrochloric acid dip to clean your iron always makes things weld better. Also, your iron needs to be the same temp as your bronze so heat them together. When brazing don't melt your bronze into your iron but instead heat your iron hot enough to melt the bronze rod when it contacts the iron. Brass works better than bronze.

You need to pickle the iron for clean surfaces and coat with borax flux.I would dilute my flux to a liquid not a paste. Flux, flux and more flux to get your bronze/ brass to flow and bond well. Slow cooing will allow the bronze to stop bubbling and give more sound results. Brilliant idea once you get it sorted out.

If you want to continue persuing this material, I might have some ideas. I used to work in a shop making tungsten drill heads for oil drilling, and since tungsten is too hard to machine in a cost-effective way, what was used was tungsten powder held together with brass. The biggest differences between what we did for that and what you did was we used a lot more brass than you'd think, and we cooked it at 2000 degrees for 2 hours. your billet is smaller so a few minutes might be fine, but when you mad ethe last one I think you were on teh right track. Just need to get it hotter and use more bronze. Don't give up on this! From what I saw, you are really on to something! And I bet you could fill that hole in your guard easily, but I'd look first to see if your tang will go through that area first. You might not need to fill it

Whenever I watched the Awe Me guys at Baltimore Knife and Sword do the bronze castings, they had a vacuum pot, similar to what you'd do for resin casting, help suck out the air and get the bronze down in all the areas. You can also do it with pressure if the temps stay high enough to remain liquid. It would definitely reduce the porosity issue you were having. Finished the video: Yeah, you definitely want pressure or vacuum to fill those spots in. Crafsman Steady Crafting has some videos on how to setup for resin casting that are pretty good. Between all that, you should be able to figure it out. A big enough pressure tank, you could probably fit your oven inside of it and maintain the heat or get a smaller induction coil that can do the same. Engineering: it's what keeps you up at night.

Love the experimentation! I ran the pour room at a ceramic shell bronze foundry and loved "playing around" to see what we could get materials to do. Will, re: the porosity issue, it could be because you don't have enough bronze available to actually fill the piece - bronze shrinks as it cools. In casting, the pouring sprue (and even intentionally added risers or feeders) are used make sure that as the bronze cools it has a reservoir of material to pull from - otherwise you can be left with gaps in the casting. For a piece this small you could create a little plaster mold with a pouring sprue to act as the feeder which might mitigate the porosity issue. Best of luck on the next attempt!

Experimentation and failure is just proof of your creativity and growth. More videos like this. You don't have to succeed at a 'cool idea' if the 'cool idea' is cool enough ;) This was a rad video.

You can always braze into the porosity holes, get the original brazing to melt and fill in the divot with new. If there's hollow spots inside after it is at finished shape you and everyone else will never know. If you melt the bronze around the holes it will flow into them and you can always add more bronze to fill in where the original once was.

Loving all these videos, Will. They haven't gone unnoticed.👀

I think this might be your most entertaining video yet. Really enjoying the struggle.

Hi will! I’m a welder and do a lot of brazing on cables for cranes and figured I’d give you what I think would be useful advice when brazing. As far as the perosity goes I believe your main problem is the scale on the steel. I notice when cutting into cables and leaving the slag on, I end up with a bunch of bubbles that I cannot get out. Maybe try soaking the wrought iron in vinegar before attempting to braze? Also, braze follows the heat so I believe your tray method would work being that the whole work piece is being heated

These are the best! A true look at the learning and experimentation curve that give life to future projects. I love what you show for the real aspect. Anybody aspiring to do what you do that watches your channel will hopefully understand that everything doesn't go perfect every time and experiments are absolutely a part of it. Keep it up!

For exactly what you're doing, I would reach out to Michael Cthulhu (the HUMUNGOUS SWORD GUY). I have spent so much time watching him fight brazing different alloys of bronze, brass, all the things, fighting those porous holes. Watching Will fight the materials is exactly what a lot of his content is. Best of luck.

The videos with "just experimentation and failure" are some of your best. I love watching the realistic creative process and seeing how you work through it all without hiding the whoops factor. Your attitude and approach are inspirational.

This is a cool idea. I have “inlaid” molten bronze into carved grooves in steel, then filed and sanded it flush and blued the steel. That worked so well that I had the idea to try what you are doing, but with steel cable instead of WI; however, I have never pursued it. I like the organic potential here. I suspect it would help if you could get your wrought *really* clean and scale-free before you started.

Hey man, don't apologize for the failures. That's most part of experimentation, and one of the things I, personally, like most about yours and Alec's videos. You guys show the real deal, the success and the mistakes. Keep up the good work!

All I can say Will, is that I'm absolutely proud to see you take on the American dream that you believe in and do it. You give all of yourself with everything you do. Thank you, keep up the good honest work work.

I would try silicon bronze tig rod. If you have a tig welder that could help more pinpoint where you are trying to fill the gaps. I have used it to repair cast iron in the past with some success. You can really get it to flow into cracks.

Props to everyone in the comments, thank you all so very much for sharing your knowledge! You all seem to have something astute to share. Blessings to you all in your endeavors!

I'm glad you're willing to share these experiments with us. Normally with blacksmithing on KZfaq all we see is music playing as someone hammers out perfection in a string of cuts between processes, and when I've seen blacksmithing in person it's been very consistent, repeatable work meant for showing an audience how blacksmithing "used to be". It's great to get insight into the process of creating something new.

I actually enjoy watching trial and error, I learn as you do. You don't have dramatic beauty shots at the end, but if learning something was the goal then you accomplished something.

Well... I guess I’m not going to bed yet

oh man I love this kind of material experimentation 😊 Try a bronze powder melt. Ofcourse a powder has a lot more volume than its melted form, but maybe melt bronze powder a couple of times in a row on top of each other. Vibrate the powder in place in an encasing, and do it three or four times. Again, Awesome vid, thanks 👍

Mate, I just wanted to thank you real quick for taking the time to convert all your measurements to Metric all the time! As a European it just makes your process so much easier to follow. For me it's just way more difficult to do them myself and I never seem to get the conversions right. You're obviously super comfy in both systems and it's super sweet that you keep your EU audience at heart. Big thanks, keep up the good work!

We don‘t mind you trying and failing things, keep on pushing out these Videos you cannot learn more on a project then failing it. Love your content

Really dig the experimentation! Cool idea too. Looking forward to seeing you work the bugs out and getting a solid piece of material.

Whilst it didn’t work out this time, I hope you’ll try it again at some point. The idea sounds really cool. Also I love these type of videos. Experimenting and failing is still a great learning experiment and makes you a better person!

You're like the Alex French Guy Cooking of the metalworking world. I love your enthusiasm and your attitude of never giving up! It's fun to watch your work. Thank you!

Couple of ideas: drawing a vacuum might help, and like some others have said: put the heat where you want the material to go. Like soldering, heat your base material hot enough to melt your second material; the bronze should flow to the heat. Try heating up your iron well past the bronze’s melting point (maybe from the side opposite from where you’ll introduce the bronze) and then add bronze until it stops soaking in. I’m not an expert, but I’ve done some soldering and I would expect the concept to transfer. Good luck, Will; I think it’s a great idea and I hope you crack it!

My experience with working with lighter metals has taught me that it's the oxygen in the torch that is getting into the solder (brazing rod material), that and the air which is already there. I can make the inside of a piece of sterling silver look like an aero bar if I partially melt it with a blue flame torch. whenever I pour silver into an ingot mould I try to make sure to have some yellow in my flame, and then I give the molten metal container a few taps to release any larger bubbles In the jewellery trade, we use vacuum casting to eliminate most porosity but I get that this probably won't be an option. When I get porosity in metal, its usually because I've tried to remove cracks from a lower carat alloy of gold or silver by partially melting it, to remove the porosity I put it through the rolling mills, which in your case could be by forging it some. you look like you had some pretty serious porosity so perhaps it would take a lot of forging and you might end up splattering bronze everywhere. I'm surprised that melting the bronze in a container and then putting it into the kiln didn't work. My guess is it's the air in those crevices that is preventing the liquid metal from flowing in. I know that casters in jewellery use vibration to help remove bubbles in investment, perhaps this could be experimented with. I'm aware that this is a messy information dump and that you probably already know a lot of this stuff, hopefully the time that I've spent making mistakes can help you save time in the future when you (hopefully) get more time to experiment with this cool idea. Love the content man.

Such a cool idea. Personally, I would reach out to Robinson Foundry. He has done a lot of interesting casting with different materials and may have an idea of how to make this work better.

Will i must say that i love that you still post videos like this! Even though you didnt get the results you were looking for, this is what learning is about, trying different things even if it doesnt work. From my experience with braising the material needs to be very clean when you start and having the iron hot enough to melt the bronze on its own means you dont need to use the torch creating different patches of hot and cold in the piece and the expansion and contraction that comes with it, just an idea but i love that you are still attempting things like this and expanding your knowledge 👊🏻 keep up the great work!

Never apologize for "experimentation and failure" videos. They are my favorite! It's all about the process, not the end product.

Something you could do is cut large grooves 1/4 inch deep into the wrought iron and then fill up the grooves with brazing rod

Really cool concept! Looking forward to seeing you try to develop the idea more!

Making things that you are already familiar with is great, but the real learning and fun comes from these kind of experiments. You just never know where it will lead you to. Although at art school my pottery teacher didn't seem to agree.

I did something similar with mild steel. I soaked the steel in muriatic acid, then I used soldering Flux and it worked well.

Grind out the cracks almost fully then braze in the bronze. That's how they fix castings.

What an amazing material concept! I hope you can get it working. I'm seeing a lot of suggestions to use pressure or vacuum, which works well for resin and silicon, and that sounds like a way to go. That or just way more heat in the wrought iron when casting

Never apologize for showing us experiential methods. I know you will be successful on this and can't wait to see it

If you want to have another go there's a few things you can try. Without a vacuum furnace though, I think you'll struggle with this one. First thing I would do is get the wrought cracked, but pay attention to how it's cracking and the orientation it will need to have the air not get trapped. If it looks like there won't be a good orientation, get it to crack more. Next thing I would do it make a container for it thats a U shape and chuck the iron in one side and then fill it up completely with flux and let that cook for a bit. You need to get the oxides off the surface. Then in the other side of the U shape pour in your bronze. That will allow it to fill from the bottom and push the flux out the top. No air, good oxide free surface and should give a decent result. You then just need to keep it hot for a while, above the brazing temperature, to allow everything that's going to bubble out a chance to do so.

when you first described it i imagined you using a press to splinter it, and then casting the brass into/around it. alternatively putting the shards/splinters inside of a mold and then filling it with the bronze and letting the whole thing soak in the forge to let the bronze fill in all the gaps. (and as i finish typing that you got to attempt two lol) try using a sand mold that should let you get it all nice and hot with out the spill out. i would have thought the quenching would have done way more movement wise with the brass being so much more thermally conductive. i did a little bit of work with high tech ceramics and what your trying to do pattern wise. you want the wroght iron to be splinters (so im guessing youd need to shatter it to get those so harden then crush?) once youve got the shapes you want, your basically just casting them inside of bronze (so use a sand mold, pour a thin layer of bronze, then place all the splinters, then pour bronze over it and then let the whole thing sit just above bronzes melting point. it should do similar to ceramics and seep in to all the openings. (you need to let it sit for hours) we were melting carbon and titanium so our temps were way hotter but we would let things sit for 3 hours for the titanium to seep in to all the gaps. oxidation might be an issue though. we used powders and used a crazy hydralic press to force the whole thing in to a tile using a parafin wax as a binder that just burned out during heating. if you attempt this again, id try to use bronze powders and small splinters of the iron like 1" long and like 1/8" wide (maybe wrought iron nails?) that way you can sort of arrange the pattern you want (bending some could be cool)

Using an induction heater to heat up the piece during casting could allow you to make a vacuum chamber around it easier, as induction heaters can be smaller

I think there is good value in showing what doesn't work and not just the stuff that works. Way to many people only show off their perfect results.

Love to see the innovation. These videos (although you feel like you got nothing done) are so important and it is so cool to see mad scientist Will at work!

Pressure chamber? Like what they use with resins?

Keep up the great work that is an awesome idea and I can't wait to see how it turns out when you come back around to it!

Learn to love your failures! You can learn so much more from failing in the right ways than you can from easy successes. Seems like you’re in the right headspace here! I have tons of respect for anyone who can incrementally fail like you have and at the end say “I’m not giving up on this, I’m just going to come back to this later.”

I see no failure here, I see a bunch of time spent learning. Thanks for sharing!

Experimentation is not a failure: You've learned a lot about what doesn't work, which has formed new hypotheses about what might work. Thanks for sharing this very cool project!

Your dedication is noteworthy and makes for good intertainment and ditto inspiration. Don't consider it failure, that the project didn't come along this time - you only just started. I look forward to seing more of you making the new material, "stelterite". I also think that some of the pieces with porousity would look nice used on knives with a more rugged appearance. Keep it coming👍👍👍

I think watching experiments that don’t work out is actually a better learning experience for everyone including you. We are all learning after all.

Thanks for this great video. This is exactly what I’ve been asking for ( getting back to your roots. ) showing the process no matter if win of fail we are here for the journey. Ty

I have learned a few things from some successes, but I have learned volumes from every one of my failures. Give yourself the gift of failure.

I think you're on the right track with the casting kind of idea with the big chunk of bronze and melting it because that flux on the outside of the rods is probably what's giving you porosity

Would bronze powder work better? Make a canister a couple inches taller so you can over fill it with the bronze powder then pop it in the oven just over bronze melting temp for a few hours?

I love that you share your failures as well as successes! I teach 4th grade in California and I’m always trying to teach my students a growth mindset to learn from their mistakes. Keep up the awesome work Will!

Will never give up and never call it a failure, always call it a learning curve. As a metal caster/metal smith I'm always finding new ways to attach two toned metals together. I might have a go and find out how to get it to work by another method if that's OK with you?

I see what you're after here and it would be great to see you come up with a repeatable process. I really enjoy watching the process even if you don't nail it the first time (or two, or three...). Stay at it and keep us posted. Grace&peace.

Been a long time fan and... it's awesome that you show the little failures. A lot of people are scared to do that, but you only learn from failures. :)

You try, you fail, you try, you fail. But the true failure is when you stop trying. This is an amazing concept, I really want to see if you can make that wood grain, especially filling those tiny cracks!!! My first suspicion is that the bronze you've been using, off gasses easily when liquid, and that causes the voids to form. Troubleshooting Ideas: 1. Try different known types of bronze, ie aluminum bronze or something. 2. Buy a chicken. 3. Try and melt the bronze and keep it at a higher temperature for an extended amount of time to try and boil off the volatiles. Then pour. It might help avoid creating those gas bubble voids. 4. Set your oven to 350 degrees and season your chicken with your favorite seasonings. 5. Maybe the bronze needs to be just above the melting temp? My thought here is that the volatiles are off gassing say 25-50 degrees hotter than the melting temp. Try and find the exact melting temp and try and keep it close to that temp when you pour. Same goes for your iron bed, keep it close to the melting temp of the bronze. Playing around and staying within tighter tolerance temp ranges might stop the off gassing. 6. Baste your chicken while cooking every 15 minutes with chicken stock, butter and seasonings. 7. Try and clean the surface of the iron with a wire wheel, and put borax on top to keep the iron surface from reacting with the liquid bronze. 8. Thanks for reading this far. 9. I've seen it mentioned in the other comments, vacuuming the cast might be an option. This sounds really expensive tho... 7. Cook chicken till it reaches 160 internal, rest for 15 minutes under aluminum foil. 8. Sit down and enjoy chicken with friends because I have no idea what else to suggest if none of the suggestions helped.

Loved it all, this is how you learn, if you don't have failures you will never really succeed.. For me failures made me try even harder also by them you learn, what not to do, so to fail is also to win.. Thank you for sharing, my wife & I love watching..

I love this video! I love to see the experimentation, the creative process, and the failures. So often we watch nothing but successful videos from blacksmiths and it can get to where you think they never experience failures like this so it's a real breath of fresh air to see the risk taking and the inevitable failures here and there in the process. That's how greatness is found! Bravo!!

Experimentation and failure are all well and good when you learn something and it absolutely looks like you learned a lot and are ready to improve the methodology. Looking forward to seeing what you can do with filling split wrought iron!

Experimentation is fun! It’s not a failure! It’s all part of the process! These are absolutely my favorite videos of yours! Please keep experimenting! ❤️

I really enjoy the experimentation videos. I'm glad you posted it instead of just going, "it didnt work perfect so this video is getting deleted." keep it up man!

Experimentation and failure is the only way to discover new, unique ways to do things. Bravo! How about taking two separate pieces of wrought, braze a coating of bronze on the "female" piece and then add more flux and clamp/weld the "male" piece on top. Then give it time in the oven to melt the bronze again. ???

Extremely interesting video!!!😃 This is definitely one of your most captivating videos! And reading the comments afterwards is pure learning! Thanks SO much, Will!! More of this type of videos please! Best regards from your friends in Norway!!

This is the first video of yours I've seen with you alone in your own shop. Liking what I see. And minor point, I love that you don't have wall to wall blaring music over every job you do. I love the sounds of the forge. I find it all very soothing. Keep it up. Subscribed.

No failure here, Will. You just found ways that don't work. God Bless you.

This is such a cool idea, and it was interesting to see your experimentation. Good luck getting this to work in the future, and I hope I get to see it!

You could try wrapping the wrought iron and copper in a welded container and heating at a cooler temp to get cracks and flowing copper. I do recall a forge welded copper and damascus video. Didn't turn out perfectly had leaks but was at a much higher temp. The cracks would form but the copper would mesh into them and as the wrought iron cools the copper would have time to stay liquid and flow into any empty spaces before becoming a solidified piece.

I just had another idea Will! What if you got solid bronze wire and also solid steel wires in different diameters. Bundled those together in a canister and used bronze metal powder to completely fill up all the voids. Then you heat it up to melting temperature for the bronze to melt, but not the steel, and then let it cool down. Once the canister is formed into a solid billet, you should be able to then work it down by forging it and get some really cool damascus style designs with it, and would look like your wood grain that you wanted. I would not recommend putting it in the forge, but maybe putting it in the kiln to make sure it's not getting too hot and melting the bronze. It would definitely take a longer time to do, but you want to make sure it's hot enough to forge without getting too hot and melting the bronze. That's why I wouldn't put it in the forge to heat it up as the outer layers of bronze may melt before the inner layers get hot enough to forge out. I hope that makes sense.

Make a crucible trough. Put the handle inside the trough. Make sure the trough is deep enough to cover the handle plus a couple inches of bronze layed cold on top. Put it in your oven (with flux) at the right temp. Let it cool slowly. Grind excess bronze off. Full depth penetration with a little jig.

If you can find the parts, rig up a heat-resistant vacuum chamber using some ceramic bowls and a high-temp seal. Take your bowl from the last bit, get it nice and molten, place in vac chamber, and pump it down. This might be enough to pull out the air bubbles that are trapped, and give you a much more solid part.

Saying that it's a failure is wrong, it was a learning curve, you've tried multiple ways, and so far it has been close, maybe like you said, a little bit more time, great video mate 👍🏼👍🏼🇦🇺🇦🇺🦘🦘Cheers from Melbourne Australia

I really appreciate seeing your experimental process. Very educational.

Two approaches 1. Take a billet and drill holes in it like a cheese grater pattern. Stick it in the forge and then put it on the anvil. The goal here is to stretch the piece in order to get the circles to form into ovals and then further stretched into lines. If the circles encourage splits, even better. Once you have enough lines of grain, pour the bronze over it to fill the lines. Then surface grind. 2. Beat the hell out of the w-iron at the ends not the center. The ends are weak and will split more. Once splits begin to form, don’t encourage them. Press the iron together and work the center. Repeat this process to get more continuous line splits, without completely separating off chunks. A large flat rectangle would be ideal. Pour molten bronze on one side. Surface grind. Then repeat on the other side. I don’t think you’ll be able to get bronze to settle all the way without gaps. Iron conducts the heat away from the molten bronze and causes it to solidify to quickly. Any air under neath the bronze would just expand and bubble if you were to surface heat. The first method is likely to held the best results.

Try taking peices of brass rod and powdered wrought-iron, putting it in square tubing capped on both ends and then heat it that way. It will allow the brass to flow throught the whole thing. Combined with using a vacuum pot you should have great success.

I love the experimental stuff. Keep diving down the rabbit holes.

Forge the iron really hard, have it break into dozens of parts and randomly lay those pieces into a casting mold. Pre-heat the mold to approximately 1100 degrees, then pour the bronze into the mold as if you were just creating a brick. The bronze should pour at about 2000-2200 depending on the makeup. You'll likely end up with a higher bronze percentage than you were shooting for, but the air pockets would be far less likely. Could look pretty neat.

I feel like having a container full of molten bronze ready and then adding a pre-heated piece of cracked cast iron to it, and re-heating it and keeping it at a temperature that the bronze remains molten for a few minutes to let it really get into as many cracks and holes as possible, then cooling it slowly, cut away the excess. If that doesn't do it then well.. good luck. Filling all the holes inside the cast though is going to rely on the holes/cracks going all the way to the surface. Maybe collab with a ASMR type scrapper/melter/recycler in your area could be interesting?

Centrifugal is a great idea if you have a setup, but might I also suggest a vacuum chamber or pressure pot if you can get access to one. Either should work to remove or reduce bubbles / cavities. My thoughts are that if you get the bronze molten and in the cavities as you did with your kiln, but go over melting temp to buy a little time, then transfer to either pressure pot or vacuum chamber then either quickly pressurize (which is easily done) or quickly pull a vacuum (less easily done), before the bronze falls below its melting temp, the trapped air will either find a way out (vacuum) or compress greatly (pressure pot) and the bronze will solidify in that position. Looks like you have plenty of suggestions to work from though.

i can see what you are trying to do in my head and my gosh it would look so nice when you finally crack the method. keep at it, it's going to be awesome

You haven’t failed. You are learning what doesn’t work. I know they sell brass powder. I wonder if you could take the iron pieces in a canister and fill the voids with brass powder and compress if that’d work. Or maybe use a crucible. I’ve never done either, it’s just a thought. You’re doing the right thing experimenting and I would wager inspiring other makers to try

Vibrate the table with a power tool, sump pump, etc or something, to get the bubbles moving and exchanging place with the metal instead of remaining trapped and causing voids.

Great video, really enjoyed it in spite of not ending in success. I'm hoping you'll do a "Part II' video of your next experiments for this after you get past this next blade show! Personally, I think melting the bronze into the wrought cracks with the evenheat is going to be the winning approach when you find the best bronze alloy and the correct evenheat temperature and 'cook time'. I would also consider doing it in multiple heats, starting with a small amount of bronze of the first heat and adding small amounts of bronze on successive heats to minimize porosity and air pockets. Good luck!

Great video. Love to see the process when it isn’t glossed over. Would like to see you try more of the bronze brazing!

I think the last iteration was on the good track. Make a canister, weld the iron to the bottom, and put a lot of bronze powder on top to seal it from oxygen. I would definitely dip the iron in HCL to remove oxides. Then I know, it is a bit extreme but after you take it out from the heat treating oven and the bronze is still liquid you should put it in a vacuum chamber and let the thing cool down in a vacuum. Maybe, the temperature of the heat-treating oven should be a lot higher than the melting point of the bronze in order to give time for the vacuum to act.

I'd suggest buying the flux separate from the bronze rods, and pre-loading the iron with that. Get your iron boat, melt the flux into it, but not burn the flux, and then add your bronze and come up to temperature.

Well done on a thorough exploration of a long-standing idea. Awesome tenacity!

This video, experimentation and failure, is how you learn. (how we learn watching you) Your subs will love how you are showing real work and not some polished perfect absurdity. Thank you 😀

Interesting idea. How would it look if you twisted it? Also what about bronze powder and do a like a canister damascus?

I have an idea. Is there any way you can do what they do with concrete to remove air pockets? Maybe create some sort of high temperature vibrating dish or plate? Something that you can set in the forge that you can put something on or in that will vibrate and cause the air pockets to be removed from the material when it's molten. Maybe one of those chisel attachments for a vibrating power tool? Just welled the part that attaches to the power tool to a plate with some ridges to keep the canister from going all over the place and vibrate the plate. You can even test the idea with a clear glass and other types of viscous material that would replicate the molten bronze before you actually put molten bronze in it. Maybe something like glue or honey or whatever? Maybe instead of a vibrating plate or canister you could use a rod of temperature resistant material and just shove it into the canister and vibrate it? Kind of what paleontologist do with electric toothbrushes? Inside most electric toothbrushes there is a small metal rod almost a needle with a metal ball at the end of it. If you could make the rod longer you could shove that vibrating metal ball into the molten metal canister and vibrate out the air pockets like they do with concrete.?

I love watching you experiment with these materials

I love this idea and it would look awesome! Please try again some time. I might have to try myself too ;) Thanks for sharing this!

It’s so cool watching you figure stuff out, keep on trying to discover!

I might have a suggestion for you. Try sticking the wrought-iron in a crucible with enough bronze that it fills up completely, that way leave it for long enough and you shouldn't be getting any air pockets.

When you pour concrete into a mold they vibrate or tapit to release air bubbles and get them to move out. Maybe after a good cleaning, pouring the bronze in while its liquid still tap it to replace the bubbles ?? Really enjoyed watching this

Materials engineer here with some thoughts on things to try. Use flux for starters. Get some fine bronze powder and pack that in the voids cold then bring up above brazing temp. Heat the iron/bronze billet in a low oxygen environment (sealed canister or something) for a long time above brazing temp, with induced vibration if possible. Maybe some combination of these will get you the results you want without having to build a fancy complicated machine. Doing a mokume gane type technique might also be a simpler way to combine the iron and bronze into a desirable pattern. Hope that gives you some more ideas to play with! Love your channel!

Oh wow, almost missed this fun vid. Loving all the content you're cranking out! Thanks for sharing your work. Looking forward to the results of the project