VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Model Specific > RV-4
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 02-08-2019, 09:56 PM
FinnFlyer FinnFlyer is offline
 
Join Date: Aug 2018
Location: Bell, FL
Posts: 156
Default Pouring elevator counterbalance lead

Anyone have experience pouring the lead?

Trying to keep tail as light as possible I figure that if I pour the lead all the way out into the front of the tip it should reduce the amount of lead required.

Drill up a hole in E403 to 3/4 or 1" near tip, put alum foil in the fiberglass tip, clecko it on, cover inside of tip with a board, tip pointed down and pour the lead into inside opening between board and E403.

The question is: how well does lead flow and how fast does it solidify? Would a 3/4 or 1" hole in E403 be enough for the lead to flow from inside to outside of E403 and fill up both sides to same level before the lead stops flowing?

Finn
Reply With Quote
  #2  
Old 02-09-2019, 07:00 AM
airtractor8 airtractor8 is offline
 
Join Date: Mar 2006
Location: Dardanup. Western Australia
Posts: 145
Default

Quote:
Anyone have experience pouring the lead?
Yes, I built an early RV6 kit and we had to do that.

Quote:
Drill up a hole in E403 to 3/4 or 1" near tip, put alum foil in the fiberglass tip, clecko it on, cover inside of tip with a board, tip pointed down and pour the lead into inside opening between board and E403.
A 3/4" hole will be more than enough. Molten lead flows just like water and you will have heaps of time to do what you need to before it solidifies. I did not do this with mine. I just poured the inner and outer side of the rib separately.

The problem you will have is final balancing and securing the lead to the elevator rib. The plans probably show this( don't know, I built a RV6 ) but you need to secure it with two AN3 Bolts at least. Lead is easy to drill if you go SLOW on the drill speed. I used a wood arbour bit like this one https://ffsupply.com/product/wood-bit-arbor/ to cut a level surface countersink on the inboard side of the rib so the bolt heads would clear the horizontal stab outer rib. It will cut easily if you use low speed and low feed.
Make sure you over balance it to allow for the weight of the elevator paint and trim servo( If you have one).

Good Luck
Cheers
Graham

Last edited by airtractor8 : 02-09-2019 at 08:24 AM.
Reply With Quote
  #3  
Old 02-09-2019, 08:08 AM
Marc Bourget Marc Bourget is offline
 
Join Date: Apr 2009
Location: Stockton, California
Posts: 209
Default

Check and then monitor your temps. Don't get too high. Once it flows well, stabilize the heat
Reply With Quote
  #4  
Old 02-09-2019, 08:46 AM
FinnFlyer FinnFlyer is offline
 
Join Date: Aug 2018
Location: Bell, FL
Posts: 156
Default

Thank you Graham.
That is encouraging.

The (old) drawing show two 1/4" coarse bolts and nuts embedded in the poured lead.
https://drive.google.com/open?id=1jB...fkx7NAT1TaF88l

Between the 3/4" hole, the opening at the tip (removing baffles there), and possibly a few additional smaller holes in E403 connecting the lead on both sides, I think the lead will stay firmly in place. The lead will be fully supported by the skin and fiberglass tip, so the connecting areas of lead will only be to hold outside/inside parts together. Still probably would be a good idea to add a couple of bolts and nuts.

Thanks for the the tip on the spade bit for drilling (or removing lead later).

I will have the servo and mechanism in place, as well as additional 5 oz for vinyl or paint, when determining lead needed.

3M 1080 vinyl is 150g/sq m or 0.5 oz/sq ft. I don't if a light paint job could be made lighter?

I do intend to mount a 3/16" or 1/4" rivnut on the outside in case I later need to add more weight (big washers).

Finn
Reply With Quote
  #5  
Old 02-09-2019, 08:57 AM
FinnFlyer FinnFlyer is offline
 
Join Date: Aug 2018
Location: Bell, FL
Posts: 156
Default Lead temperature

Quote:
Originally Posted by Marc Bourget View Post
Check and then monitor your temps. Don't get too high. Once it flows well, stabilize the heat
I've never worked with lead before. This particular lead is "Lead Ingots from Wheel Weights".

No clue what the temperature should be. I guess I'll put it a small coffee can, heat it with a propane torch until it flows to an even level in the can and then pour it? Or should I get a cooking thermometer and heat to what temp?

Finn
Reply With Quote
  #6  
Old 02-09-2019, 09:51 AM
abwaldal@gmail.com abwaldal@gmail.com is offline
 
Join Date: Jan 2017
Location: Battle Ground WA
Posts: 10
Default

No cooking thermometers in lead. It melts at 640 degrees. Poof goes moms thermometer. pours easily wear safety glasses, gloves, don't drink whats left over. ha ha
Used to make sinkers bullets etc for past 60 years. Ain't dead yet don't breath fumes.
Oh by the way its hot and burns easily
Reply With Quote
  #7  
Old 02-09-2019, 12:06 PM
Christopher Murphy Christopher Murphy is offline
 
Join Date: Feb 2007
Location: colorado
Posts: 830
Default Do it like the manual says

Just rivet in a small “dam” where the plans indicate use the 2 course thread bolts and skip the large hole. Make a single pour for each side (4 total)

Works good lasts long time. And its easy

Cm
__________________
RV-4 "Mr. Twister"
Pitts S1S "Mexican Red" sold and missed
Mr. Twister Airshows
Rocky Mountain Renegades
the mission... have fun.
Reply With Quote
  #8  
Old 02-09-2019, 12:16 PM
Robin8er Robin8er is offline
 
Join Date: Sep 2015
Location: Socal
Posts: 304
Default

Be careful with wheel weights, most of them aren't made out of lead any more. The old ones are.

Obviously use in a well ventilated area and try to to breath it.
__________________
RV-8
N695RA Reserved
Emp and Wings done, working on Fuselage.

Born to fly, forced to work
Reply With Quote
  #9  
Old 02-09-2019, 12:22 PM
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 8,223
Default

Quote:
Originally Posted by FinnFlyer View Post

Drill up a hole in E403 to 3/4 or 1" near tip, put alum foil in the fiberglass tip, clecko it on, cover inside of tip with a board, tip pointed down and pour the lead into inside opening between board and E403.
I haven't ever personally tried this method but my guess is that even with alum foil, you will end up replacing the fiberglass tip after you are finished........

I recommend following the instructions.
No need to measure the lead temp. Heat until it is melted and then (carefully) pour.
__________________
Any opinions expressed in this message are my own and not necessarily those of my employer.

Scott McDaniels
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
Reply With Quote
  #10  
Old 02-09-2019, 01:01 PM
FinnFlyer FinnFlyer is offline
 
Join Date: Aug 2018
Location: Bell, FL
Posts: 156
Default Experimenting

Thank you all for the data and advice to follow instructions.

Obviously the fastest would be to follow plans, but this is supposed to be recreational/educational. And I really want to save weight where possible (without spending a fortune on a titanium tail spring).

So fiberglass (resin) deformation would be a real issue. Getting fancy I could coat the inside of the tip with fiberflax sheet (I think that's what it's called) and then the alum foil. Or submerge the tip in water (heatsink). Or put the tip in a small container with gypsum (sheetrock compound) and let that harden -- that should hold the shape of the fiberglass tip. BTW, these are old gel coated tips.

Finn

Quote:
Originally Posted by rvbuilder2002 View Post
I haven't ever personally tried this method but my guess is that even with alum foil, you will end up replacing the fiberglass tip after you are finished........

I recommend following the instructions.
No need to measure the lead temp. Heat until it is melted and then (carefully) pour.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 06:56 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.