Nose weights

I am trying to finish this up right now, and came across this thread. Anyway here is my contribution to this thread. I've also done a 1/48 scale PBY Catalina. But here is a pic of the B-24D in 48 scale. I've always used the lead sinkers.

 I have a bunch of sinkers in front of the dash board and a lot more in the compartment behind the nose wheel assembly. I extended the wall behind the nose wheel up to the floor boards above it for that purpose and used tweezers to add weight through the bomb bay into the nose wheel compartment and I super glue them in place. I stacked the tail pieces on the back then used the sinker bags balanced on the nose to see how much weight I would need.

I use the split-shot fishing weights and lead solder. I like using the split-shot because you can cut it and smash it with small pliers easily to fit in small areas. When I built a 1/48 scale P-39 that had the nose open for the gun bay I filled the ammo can with cut up shot then sealed it with putty, made the ammo belt using copper wire cut and shaped like the 37mm shells, smashed the split-shot into flat pieces and lined the inside of the spinner, the firewall and the underside of the gun deck with 2 layers. Finally I used a lead solder and filled in the hollow area inside the front tire. On aircraft that has a glass nose (B-25, B-29, B-26, B-24,etc) I find that by filling the small voids can provide enough weight to keep the tail up. It also helps to have precision weights so you can see how much weight is required to offset the tail. I piece together the plane with tape and figure out how much weight is required then I balance the weight on a scale with split-shot. This gives me an amount of split-shot that I need to use.

I have ever had the plastic landing gear bend from weight because using the above method keeps the weight down to the minimum required. I tend the keep the aircraft balanced to 51/49% balance.

There is a product along the lines of that powder tungsten,  Its called LIquid Gravity from Deluxe Material. I haven't tried it yet, but cost and quantity is more reasonable for modelers, as its sold specifically for this job.

Melting and pouring works well because you don't have air pockets.  Years ago I used to buy lead and beat it up with a hammer and work it in to the shape I wanted and then press the softened lead in to the nose cone of fighter jet  models. I knew a guy who had access to a machine shop and was able to get his hands on a bag full of aluminum and steel powder on and off and used to mix the powder in to a slow set epoxy and pour it in to 1/48 scale as a weight. It seemed to work .  

The problem is not in getting lead or other high density material, it is the packing factor.  For the kits I am talking about, the available volume needs to be almost completely full.  One cannot just chop lead into chunks and glue it in- too much dead space left!  That is why we are talking about making molds and melting the metal.  Gluing odd shaped chunks in does no good if half the space is taken up by air due to chunks not fitting together well enough.

Huumm!  That might work!

Has anyone ever tried to just mold the lead weights, beat'em into shape with a hammer?

I've always used "split shot" fishing sinkers.  You might also try bird shot or .177 cal pellet gun ammo.

I find square weights no better than spherical for applications requiring high density- the space available is not square/rectangular, so packing density is still a problem.  Usually the space left open is a truncated cone with a segment chopped out.  Somehow, melting and recasting seems about the only way to go.  That is why kit mfgs should do it.  Lead and other low-temp alloys could be easily die-cast in kit production.

Lets face it, it is the tri-gear planes that need nose weight, but tri-gear ships also have less volume in nose because of the volume the gear stowage area takes.

Don, sand casting is picky with the type of sand and how you handle it.  You also need to be completely dry or else you could get an explosion of steam.  I would recommend a lot of research before trying a sand casting project. Good luck.

John

Don, you can get square lead weights from the pinewood derby car section of your LHS... at least you should be able to. If I remember right, they come in a sheet that allows you to easily break off the amount you need, kind of like a Hershey's candy bar...

go to your tackle box and drag out some sinkers

Might be time to add a super magnet to the aircraft display base and a small amount of steel in the nose of the aircraft.

I've never tried searching for Tungsten powder.

I see it advertised

http://www.tungstenheavypowder.com/Tungsten_Heavy_Powder/Tungsten_Heavy_Powder_Products/tungsten_heavy_powder_products.html

but do not know if small quantity sales are available.

I must be old school. I mainly use lead shot and super glue. If there's a spot for an adhesive backed metal weight, I'll use that.

Maybe I should try the sand casting.  I tried making plaster of paris molds from carved wood patterns to make weights for the A-37 I am working on.  I have always had trouble with plaster- it cracks on my.  My mold had two cavities, one from right pattern, one from left.  I did get a good weight from the right mold, the mold in the area of the left pattern just fell apart and crumbled!  Got half the weight I need, anyway.

I guess I should learn to do sand casting anyway- it is something I always wanted to learn.  For a non-critical casting like this, I assume I can use any sand.

I make a casting of lead.  Using the  kit part, make a mold from aluminum foil by pressing the foil into the cavity of the part. .  Place the foil mold in sand (to keep the shape), melt some lead, and pour it into the mold.  Epoxy the weight into the part.  Sometimes you have to place lead in every open spot forward of the center of gravity.  In the engines, the nose, in wheels, under the floor.  Once in a while I drill out the center of the landing gear strut and insert wire to stiffen the parts against the weight, (started doing that after the nose strut of my B26 collapsed)

works for me

I have found that the larger the scale, the easier it is to place weights in the nose-cone section of jets.....particularly in the case of the 1/48 Revell F-105. For this bird, I used a lead bullet component, as it is cone-shaped already, and then secured it from behind with some silly putty.

cvsusn

Don,

I was just at Michael's where they had the Pinewood Derby material on display. I failed to notice any powders, but saw several sizes of weights to include small disks that appeared to be lead. I was there for other reasons and just took a cursory look to reminisce. May be worth another look for you since it may be Pinewood Derby time.

Carl

Yeah, I have seen the seperate weights, but the putty just sounded like the ideal thing.  The space available in the nose of some kits is just so odd shaped that I frequently cannot pack enough of discrete weights in.

You can also get lead weights with adheasive backing.  Thin enough to bend to conform to the inside of the fuselage.

www.amazon.com/.../ref=sr_1_2

Don,

I was just at Michael's where they had the Pinewood Derby material on display. I failed to notice any powders, but saw several sizes of weights to include small disks that appeared to be lead. I was there for other reasons and just took a cursory look to reminisce. May be worth another look for you since it may be Pinewood Derby time.

Carl

Along with lead fishing weights there are also tungsten weights that came out several years ago.  They are hard but extremely heavy and not as bad for you as lead.  It's 1.7 times heavier than lead due to it's density so you can stuff more weight into a smaller space.  Walmart used to carry them the last time I checked.

I also use modeling clay and sometimes RTV. I fill the space where I want the weight to go with the clay, say each half of the fuselage nose or a prop spinner. As stated above oil or wax the surface so the clay will release and remove the formed piece. I place it in plaster and let the plaster harden. When the plaster is cured I pull out the molded clay and fill the plaster with lead. When the lead is cool remove it from the mold and clean it up to fit the intended space. I have also made molds out of high temp RTV and used them for multiple castings. I have also carved molds out of wood for simple molds. I have a small ladle for melting and pouring lead that came with a mold set for lead figures (lead soldiers). Take care as hot lead hurts.

Can lightly oil up the space you want to put it in, make a modeling clay plug to fit it, pull it out, mold a clay chunk over it and pull out the plug.  Clean out the oil (Try olive oil) and pour your lead.  Just do it with good ventilation.

Smooth On (known as a resin company in modeling)

www.smooth-on.com/.../index.html

Rex

For you that melt lead, how do you make the molds?

Yes VN750 I have experienced the bowed out landing gear as well as collapsed gear due to the weight. A solution that works, other than aftermarket metal gear, is to drill out the gear leg and put in a metal pin, e.g. straight pin or piano wire. This stiffens the gear and gives it strength. This is a tedious process and is not a solution for every model. Sometimes you have to bite the bullet and use a clear piece of sprue to hold up the tail, or mount the model on a display base and tie down the nose. I use a fine wire and put it behind the nose wheel and through the base.  

Ever have the landing gear buckle over time because of the weights?  I't warmer in Florida but a friend of mine showed me models with bent landing gear due to the weights.