Converting Pour Molds To Injection?

[FuzzyGrub]

I have two Dels pour style stick molds with 1/2" sprue hole and one with 3/8". My injector has a 5/8" standard injection tip (BassTackle). Has anyone drilled these out successfully on a drill press? I am a little concerned with the drill jamming at the mold halves, and throwing mold and vice across the room. I would like to hear some success stories and the details that made it so.

Or is it better to just get another injector that better mates with them? (ie Dels)

Or will Basstackle make a 1/2" tip? (and still drill the 3/8" sprue)

Edited December 28, 2010 by FuzzyGrub

[Vodkaman]

An adapter is probably the best solution, made from RTV. Ghostbaits (Jim) has run with the idea and it works. This would involve no mold modifications, thus maintaining mold re-sale value. Here are a few links to discussions:

http://www.tackleunderground.com/community/topic/17843-bears-hand-injectors-do-they-work-on-bobs-molds/page__p__135237__hl__adapter__fromsearch__1#entry135237

http://www.tackleunderground.com/community/topic/20222-senko-molds/page__p__151035__hl__adapter__fromsearch__1#entry151035

http://www.tackleunderground.com/community/topic/20428-injection-molding-pop-or-resin/page__p__152394__hl__adapter__fromsearch__1#entry152394

I too would be nervous about drilling, but it would be do-able. You need to investigate drill speeds for the job.

Dave

[Frank]

I have made a tip like you want. I put it in my lathe and tapered it to a cone, it still is 5/8 on the top but after 1/8 " it starts to taper. Ask kevin if he can taper a tip like that for you. Then you will have a spare tip you can use on any mold you have. Frank

[FuzzyGrub]

Dave,

I read the links, but was hoping to find a pic. Not 100% sure what that would look like and in my mind, I am seeing the center passage getting restricted when you compress against the mold. That might be a good solution for another pour mold that I tried the injector on, Bob's Buzz Frog. While it does have a 5/8" opening, it tapers quickly and has a shallow sprue. I was able to do it, but the tip to mold seal was poor.

Frank,

I see that Jacob's Injector has a very tappered nozzle. Dels, have a tappered edge as well. I don't really want to get multiple suppliers injectors, with non interchangeable parts. Given the short tip on Kevin's nozzle, I would need a lathe to do it. I might be able to find someone local with that. I will also send Keven an email and see what he could do.

Bob L,

Yea, I wish I had easy access to that type of equipment. That would be the best, though. As a newbie, I like the positive feel of the 5/8" tip fitting in the 5/8" injection molds. No question if you have a seal or not. The two injection molds I have, work great.

I also found someone had drilled and taped their nozzle and uses different tips. This looks promising. Injector tip mod I might look around the H/W store today to see if there is a fitting I could make work.

[tigerfire]

I am also very interested in an adaptor for hand pour molds.

I just purchased an injector and I only have hand pour molds. I tried injecting a few. I was careful to watch out for flying plastic! That was not a problem since the plastic seemed to cool and thicken before I could pour my second and third baits. The baits did come out fine, but I would definitely feel more comfortable with an adaptor that fit the mold.

I have a few POP molds that I would like to inject also, but I doubt they could take the pressure I would place on them. After reading all of the above links, I might make new POP molds to fit the injector and strengthen them.

I have not worked with RTV, but if I could make an adaptor out of it, I surely will try.

If Kevin has a solution and can make adaptors for his injectors then I am definitely interested in that solution as well.

[Delw]

I am too lazy to search for the post that I posted a while back,

all you need is a hand drill and a file thats your lathe right there.

goto the hardware store and find a bolt that fits in the hole of the tip, your going to use this as an arbor. and chuck into the drill.

double nut the bolt on the tip and make it tight then chuck it into the drill spin the drill and use the file to put an angle on the tip.

when using a file you need to use a coarse file(faster) with lots of soapy water/ wd 40/ oil as the alum will load up the file teeth if you dont. you will need to move the file side to side, so it cuts dont just hold it there in one spot.

now on the molds you need to do this.

press out the bolts (c clamp and a socket) get a pcs of wet and dry sand paper 180 grit works great.

put the sand paper on a smooth flat surface ( kitchen counter top smooth) and put the cavity side down on the paper and do figure 8s with it. it will sand the face flat and take out any burrs.

press bolts back into the mold with a c clamp and socket ( poor mans press)

the paper should be coated with wd-40/ mineral spirts or soap aand water, this will keep the paper from loading up.

if you dont do this you will get some extra plastic on the seam lines when injecting as the mold isnt flat.

DONT try drilling the hole with a hand drill and a 5/8 drill bit, as the holes in the mold are too big and the drill bit will grab and ruin your mold unless you have something very rigid to hold both the drill and the mold so they dont move. a vice on the mold and your hands on a hand drill WONT work. A drill press might if its a stout one and you can get it below 200 rpms.

I have two Dels pour style stick molds with 1/2" sprue hole and one with 3/8". My injector has a 5/8" standard injection tip (BassTackle). Has anyone drilled these out successfully on a drill press? I am a little concerned with the drill jamming at the mold halves, and throwing mold and vice across the room. I would like to hear some success stories and the details that made it so.

Or is it better to just get another injector that better mates with them? (ie Dels)

Or will Basstackle make a 1/2" tip? (and still drill the 3/8" sprue)

[Vodkaman]

Attached are pictures of the mold adapter that I have in mind to address your specification. It fits over the 5/8” diameter injector nozzle. It has two steps for 1/2" diameter and 3/8” diameter mold pour holes. By stepping the adapter, the nozzle will not collapse and close the pour hole. My initial idea would have been a tapered plug attachment rather than stepped, but I take your point about the possibility of collapse.

There are several ways to make this adapter. Make a wood master, make a PoP or resin mold. But this method is tedious, time consuming and has other associated problems, such as extracting the master from the mold.

I have come up with a simple solution that eliminates the need for a master or traditional mold making techniques. Make the mold from wood. By drilling a few holes in a block of wood, fitting a pin, to represent the pour hole, fashioning a 5/8 button to represent the injector housing, gluing button to plywood plate, drill hole through button same diameter as pin. Wax all surfaces, pour RTV, locate button plate on pin and push closed, squeezing out excess RTV.

I have made more pictures with more detail that I can post if necessary.

It could also be feasible to make from Husky's silicone sealant, mixed with a couple of drops of water for rapid cure.

Dave

[SHK]

Attached are pictures of the mold adapter that I have in mind to address your specification. It fits over the 5/8” diameter injector nozzle. It has two steps for 1/2" diameter and 3/8” diameter mold pour holes. By stepping the adapter, the nozzle will not collapse and close the pour hole. My initial idea would have been a tapered plug attachment rather than stepped, but I take your point about the possibility of collapse.

There are several ways to make this adapter. Make a wood master, make a PoP or resin mold. But this method is tedious, time consuming and has other associated problems, such as extracting the master from the mold.

I have come up with a simple solution that eliminates the need for a master or traditional mold making techniques. Make the mold from wood. By drilling a few holes in a block of wood, fitting a pin, to represent the pour hole, fashioning a 5/8 button to represent the injector housing, gluing button to plywood plate, drill hole through button same diameter as pin. Wax all surfaces, pour RTV, locate button plate on pin and push closed, squeezing out excess RTV.

I have made more pictures with more detail that I can post if necessary.

It could also be feasible to make from Husky's silicone sealant, mixed with a couple of drops of water for rapid cure.

Dave

way over thinking it Dave. Far easier to chamfer the injector tip with a file

[Delw]

This is why I like engineers, they go way above. ( and thats a good thing) With daves Drawing you can use it for reference on future projects as its a very good drawing and well thought out like everything he does.

on what was first posted and trying to accomplish, I wouldnt recommend adapters they are a waste of time and energy plus they are cumbersome and you have to clean them out.

just taper/chamfer the tip of the injector nozzle. All ours are tapered for this very reason, Ie hand poured molds.( I am not saying buy my injector cause its tapered cause I dont like making injectors as it takes me away from making molds) but you can taper the tip on any injector using the method that I mentioned above.A chamfered tip will fit on any size hole( to the size you chamfer it down to) wether the hole on the mold is chmfered or not.

Sometimes we over complicate things for something that is really simple, but in over complicating things you learn other ideas.

Forgot to add:

I just walked into the shop. I will snap a pic in a few of what I am talking about. or you can call the shop and I will explain how, this week our hours are wierd cause our house is being reroofed from a hail storm and I have to get the patio cover rebuilt before they show up, then I find out we got another storm coming intomorrow night with freezing rain and the contrete is being poured tomorrow.

Delw

Delw

Edited December 28, 2010 by Delw

[Vodkaman]

'Over thinking it', maybe, but it is an alternative solution to modifying the nozzle, not everyone is going to be comfortable with that solution, even though it is simple.

I have just been to my cave, chopped a block, drilled some holes and cut the pin. Sealed the block with a coat of polyester resin. It took ten minutes.

In hind sight, it was not needed to step for the two sizes. Because the adapter is RTV, if it is built for the smaller size, the rubber will seal to the mold on the larger size.

Subjects like this come up quite often. It is always a good idea to discuss them to death, explore every option no matter how impractical it may seem. This is how component designs are improved. Unlikely ideas can spark better ideas. I am not just talking about this particular thread but problem/solution type threads in general.

Dave

Post script. Just read your post Del. Similar train of thought.

Edited December 28, 2010 by Vodkaman

[Delw]

dave never change your ways,posts or pics, there is always good coming out of them at one time or another.

Remember the one guy that wanted just spruce's ran for his full round pop molds? and someone came up with the idea of using the big Golf Tees, that was cleaver for sure.

I was looking for that post a while back to repost it on one of the pop mold making qustions and couldnt find it.I thought someone even posted some pics of it.

'Over thinking it', maybe, but it is an alternative solution to modifying the nozzle, not everyone is going to be comfortable with that solution, even though it is simple.

I have just been to my cave, chopped a block, drilled some holes and cut the pin. Sealed the block with a coat of polyester resin. It took ten minutes.

In hind sight, it was not needed to step for the two sizes. Because the adapter is RTV, if it is built for the smaller size, the rubber will seal to the mold on the larger size.

Subjects like this come up quite often. It is always a good idea to discuss them to death, explore every option no matter how impractical it may seem. This is how component designs are improved. Unlikely ideas can spark better ideas. I am not just talking about this particular thread but problem/solution type threads in general.

Dave

Post script. Just read your post Del. Similar train of thought.

[TBaits]

Golf tees for the POP sprues.....excellent! Thanks for the info!

[GB GONE]

Just curious as to why you want to change the molds at all? I inject my hand pour molds all the time now without issue. As a matter of fact, if you do drill them out, you are going to have a fun time removing all of the excess material from your baits as hand poured molds are vented for hand pouring, not injection. The numerous vents will ALL have plastic in them and they ALL will be attached to your bait. The time saved injecting will be lost X 2 with all the tiny appendage removal you will have to do.

The non-fit is perfect for not being able to put the pressure on the mold like you do with hand injection. You still can feel when the mold is full and 2 color laminates are just as easy. The non-fit is almost like a small pressure relief as the plastic will ooze in the area the nozzle doesn't exactly fit into and you are done.

I have injected Bobs buzz frog molds, split tail molds and many others with no issue. Bobs split tail bait is on the bottom.

Just me, but I would not change anything.

Jim

PS This was done with my BT blending block. It is the same size as an injector.

Edited December 28, 2010 by ghostbaits

[FuzzyGrub]

WOW!, lots of input while I was out at the HW store! I will be busy reading and catching up.

I did find something I think will work. It is a brass plumbing adapter. It takes a soldered 1/2" ID copper pipe at one end and a 3/8" flare on the other end.

I had to sand the inside to get the injector nozzle to fit tight. The flare end seems to fit the molds, but doesn't drop all the way in the 1/2" sprue dels. I think I can take a little more off and it will.

I compressed and sanded the flare end threads, and it will fit the 5/8" spue molds. I have a little more work on it, and will give it a try tomarrow.

One possible issue is: it only has a 1/4" dia opening for the plastic to go through. (the nozzle is about 5/16" dia) I can't drill it all the way out as it will ruin the tip. I did neck it down as far as I could go.

It is similiar to this:

http://www.acehardwareoutlet.com/productdetails.aspx?sku=998016024&source=GoogleBase

[Vodkaman]

Remember the one guy that wanted just spruce's ran for his full round http://www.tackleunderground.com/community/topic/14968-help-with-mold/

Dave

[FuzzyGrub]

Well, I couldn't wait and did some quick pours.

The good news: the tapper works fine to filling all the various molds.

The bad news: Del was correct, cleaning became an issue. Had to always remove adapter to clean. Also, as he said, the molds will need some finish sanding to prevent flash along the seam.

Additional bad news. When plastic level in pot, fell below tip/adapter, it would only suck air.

OK, out with the adapter, and in with a tapper tip, and finish sanding of the molds.

[FuzzyGrub]

My main reason for suggesting an adaptor rather than "just" boring out the mold to fit (which is even easier for me) is that a lot of hand pour molds have no reservoir. When hand pourings its not that big of a deal because you just keep going back and topping it off, but for injectiion you have the issue of nozzle freezing, and often people are looking at injection for increased productivity which means they are busy shooting other molds.

Yes, the hand pours need constant monitoring, especialy the stick bait with 3/8" sprue hole. I quickly reach for the cup of plastic, after the nozzle freezes.