By Andrea Daley
Article #3 of 5 ON FINE PORCELAIN RESTORATION - This information is written for the amateur who wishes to just glue an item together. If the item is of great value, either sentimental or monetary, then it should be given to the attention of the professional
Question: What glue do I use to glue my treasured piece back together?
Before proceeding any further, you must realize that if you improperly glue your item and then take it to a Restorer, the cost is going to be at least doubled, possibly tripled and maybe even impossible to undo!
The most used type of glue that the amateur chooses is one of the instant glues. You know, the ones that glue your fingers together!
You line up your two pieces, squeeze some of that clear runny adhesive, and misalign the two pieces! Your finger sticks to the piece or to your other finger. As you pull your fingers away, the piece will jar and you must start over. However, there is now a dried glue of this already attached to both sides and no solvent is going to remove it. So you struggle at a second attempt using a few choice words to help and realize the two parts are still unattached and the mess has only enlarged.
Instant glues do not do the job. They have their value, but seldom with amateur repairs. The least vibration from being hand held is enough to off set it. Let's say you were lucky enough to get the pieces adhered evenly. The next problem is these glues cure so hard that any impact sideways will cause the glue to sheer. The strength to pull on it may be there, but if it were to fall over, most likely it would come apart.
The other negative quality of these glues, is that they weaken over time. Many times I have gone to test the strength, to find the item falls apart in my hands, only after a few months. Just the slightest pressure may have it come apart.
Answer : Porcelains (non-porous) - Epoxy (2-part curing adhesives)
Before attempting to glue your piece, I suggest, you read the two previous articles; TYPES OF RESTORATIONS (Article I ) and HOW TO CLEAN "FINE PORCELAINS" ARTICLE II.
Materials needed:
GREASE RESISTANT PAPER PLATES
TOOTHPICKS
TWO PART EPOXY GLUE ( 5 MIN.)
SMALL CAN OF LACQUER THINNER
0r
NAIL POLISH REMOVER
RAGS
PLAYSAND
SANDBOX (a container, larger than item, holding playsand )
MODELING CLAY
TWO OLD TOWELS
SINGLE EDGE RAZOR BLADE
Procedure Steps:
1. Place one towel underneath working
area. Keep other towel on lap.
2. After items have been properly cleaned,
align in order to be adhered.
3. Place item in sandbox for balancing.
4. Place adhesive on both sides of areas to
be adhered.
5. Place on balanced part
6. If more than one part, wait minimum of
30 minutes before proceeding with next
part of item. Reset item for balancing
and repeat steps 4 - 6. Continue until
item is completely glued.
The items must be thoroughly clean. After it has been cleaned, take a toothbrush and with pressure wipe back and forth over the broken surface to remove any small amount of porcelain dust, chips or flakes. The least part of a substance caught, will cause a misalignment.
When gluing more that one part to the other, make sure you have outlined which piece is to be adhered in order. It is very easy to glue several pieces and then to find out the next piece will not fit.
Place item in a sand box to find its balancing point. In most cases , there is a point where the top piece will balance on the bottom. It may take several maneuvers to find this point. If the item has a unique shape that prevents it from a balance point, then find the closest position for it and with a little piece of modeling clay, carefully support the two pieces so they will balance. This balancing is crucial because if you try to hand hold an item, while the glue cures, the vibrations from your body are enough to off set the piece which will prevent a strong adhesion. Try each piece with out glue, first, then, if it fits proceed to gluing.
Use the back side of a paper plate to mix the glue.. The grease resistant plates have a coating on the front that you do not want to be mixed in with the glue. It will weaken them. I suggest using the grease resistant paper plates because, the glue will not soak through and on to another surface. Also when getting into the painting stage, these plates are what will be used. Use a toothpick for the stirring. Mix the glue; stir stir stir. I find most people have to find this out for themselves. If the glue is not mixed properly, it will not hold. I suggest working with a five minute epoxy glue. (This glue can be purchased at your local hardware or supermarket store.) A longer setting glue can be used and will give you more working time. Epoxy glues are a resin with a hardener. Obtain the brand that requires equal amounts to be stirred together. Work quickly, if using the five minute epoxy. I stir one hundred strokes and then a few more. I just use my fingers, 1-10, on each one. Keep close a cloth and nail polish remover or lacquer thinner. This will remove any glue that may have stuck to your hands. I caution you to choose your set up carefully. Make sure you have ventilation , a fan in a window and protect the surface on which you work, if necessary. Nail polish remover or lacquer thinner will eat into most finishes.
When applying glue to a piece that is broken into more than two parts, apply as little glue, as possible. Do not extend to the edge of the broken parts. An excess amount of glue will ooze out the edges where the next piece goes. When the next piece is set in place, the excess glue will not allow it to align. Always stop at least a one quarter of an inch away from the edge. I apply the glue with my fingers, while applying pressure to the surface. You may wish to use a toothpick. I find using fingers will assure a tighter bond.
After the last piece has been positioned, let stand, balanced for at least thirty minutes. With a new single edge razor blade, remove any excess glue that may have pushed through onto the sides. These items have been only glued and over time the epoxy glue will yellow and the crack, in some cases will become apparent. If this is of concern, then a professional restorer with the skills of opening up the crack, filling it and then with an air brush, to simulate the design and glaze, will be able to cosmetically hide the damage. If you plan on having professional work performed on your item, then it is best to let the professional do the whole job. If an item is not glued to the professionals standards, then it will be more costly to undo the glue and restart.
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