Refacing Ampico/Amphion valves

copyright 2002 D.L. Bullock

Tips for getting to the valves:

 Use a heat gun on low setting (500 degrees F).  Set it up on the table and hold a valve block with metal 3-4 inches in front of the air nozzle for about 6-10 seconds.  Using a small pair of flush cutters grab the edge of the metal can.  Pull and if it is hot enough it should come right out with very little effort.  If not put it back into the hot air another 5 seconds.  You may need to pull one side and then the other on some valve blocks.  The old burned shellac will be very soft so you can scrape it all off after the metal seat is removed with one scrape of the back of a knife.  Never spend hours scraping burned shellac again.  The heat gun works.  Too long in the heat, though and shellac boils and burns onto the item harder than ever.  By the way, don’t burn your fingers.

 To clean up the metal seats, soak them in Methanol or full strength Top Job or diluted ammonia based antique clock cleaner solution.  Do not soak them overnight in anything ammonia based as it will eat them up, they are brass.  An hour or so is just fine, though.  All old shellac should come off leaving clean shiny metal seats.  I always fine sand the seat surfaces with 320 paper on glass to make sure they are not bent.  You can see that the sanding is even all around the hole if the seat is flat.  If not you may have to flatten them again or use new ones.  Lacquer the sanded seats with metal lacquer.  

Refacing

We cut out new facings from the finest chrome tanned leather we can find.  This leather is close grained and does not seep like most leather available for player pianos.  This is our technique for replacing leather on these valves within a short period of time.  A set can be done in about three hours or less by an experienced rebuilder. (excluding drying times)

 Cut out the inside facings using dies that add the center prick for the escutcheon nail that was used by the factory.  Cut out the outside facings using the standard arch punch.  Or purchase them from Piano World.

 Put all valves in a small tub about the size of a cool whip container.  I have several available.  Pull the stems off the wooden biscuits that are the valves.  Folding stems over usually pulls them out completely if the leather is rotten enough.  Using electronics flush cutters (wire cutters) grab the head of the nail in each valve stem and pull it out.  Try NOT to cut the nail as they are very small and easy to snip.  The stems go in one tub, nails in another.  Clean the old leather off the nail.  If you must use a new nail, you will probably not be able to get the same size and the stems will need to be drilled out or nails will split the wood.

 You do not need to remove leather from the wood biscuits.  Put them all into the tub and cover them with hot water.  Not boiling, but just hot tap water is fine.  Wait 3-5 minutes and begin pulling one at a time out, rubbing the wood on both sides with your fingers to remove all leather and slimy feeling glue.  If it does not come off easily or quickly let soak a few more minutes.  If someone used white glue, you may need to scrape it while wet with a felt knife.  When clean, put them in another tub of water.  When all have been cleaned of leather and glue, cover them with water and change the water several times to wash all residue off the wood biscuits. 

 Next lay them all out one deep on screen wire and put them in front of a fan to dry.  Dry them overnight or at least several hours.  If it is a damp day, definitely dry them overnight.  Once dry you MUST sand each one on both sides.  I use some 150 adhesive sand paper that I stick to a piece of glass.  Sand each side back and forth several times.  Look at it and you will see whether the wood is totally flat.  If not sand until it is. 

 Push the original escutcheon nails through the center prick holes of the new Piano World valve seats.  You may wish to use needle nose pliers or flush cutters to hold the nail.  The head goes on the slick side or, in this case, sanded slick side.  The suede side will have the point coming out of it.  When all faces have their nails in place, you may put them back into the stems.  Use large pliers or channel locks to press the nail into the stem.  Do not hammer it in or the nail will recess into the leather.  You only want a snug fit.  If the nail wants to slip out of the stem, in the case of the valves having been “restored” before you, you may put a dot of tacky glue or PVC-E glue on the end of the nail before inserting.

Glue the top seats suede side out to the wood biscuits on the side that has no indention.  Read the next paragraph to see how we make sure glue covers the surface but does not ooze out.  Glue two at a time using that technique and press them leather sides together.  Press them and set them aside a few minutes.  When you have 10 or 12 glued, stack 4 of them together with two pairs leather sides together and clamp them together with a standard spring clamp.  If you use smaller clamps you may clamp two only.  If your clamps are large you may use 3 pairs in a stack.  By letting the hot glue set a few minutes you will not have them skating around and you won’t end up with a facing overhanging the side of the wood when they are dry.  If you let them set too long the hot glue is too dry and if anything was not snugly glued it will not stick and will need to be pulled off and reglued.  If these facings are not glued perfectly flat there will be problems sealing when they work.

 Using hot glue (preferred) or Elmer's or PVC or Tacky glue, put a thin ring or several dots of glue on one wood biscuit (on the side with the indention in it).  Pick up another and press the two indented sides together then twist them in opposite directions.  You have too much glue if it oozes out all over.  Pull them apart and check to see that glue covered the whole flat area.  If the indention is filled with glue clear it out with a cue tip or small screw driver blade.  Press each wooden biscuit onto a leather valve facing which is in place on your glue board with the stems in the holes.

 Make a gluing board.   It should be perfectly flat. Mine is about 2 inches wide.  It is long enough to do about 40 valves at once.  Yours should have holes in it the size of the hole in the Bakelite or wood seat of the valve blocks you are working with.  With many holes in the board you can insert the valve stems into the holes and glue many valves at once.  My shop board has two rows of holes alternating between two sizes of hole.  These two sizes allow me to use the same board to glue both A and B valves using the same board for both…but not at the same time.  Also, you should have some small thin pieces of wood to put down over the glued valves so the clamps will not leave indentions in the leather top seats.  You can also cut thin pieces of large dowel to put over each valve for clamping.

As you glue the wood to the nailed facings, make sure they do not skate like three of those at the right of this picture.  Clamp them using the spring clamps and wood shields to prevent leather indentions made by clamp jaws.  

 Keep them clamped up an hour or more before using them.

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