After you receive your HTS-735 II Fluxless Brazing Rod
you should review the included instructions carefully.
Alternatively you can bookmark this page and review it here.
Application: HTS-735 II Fluxless Brazing Rod was developed for aluminium, magnesium, cast aluminium, and cast magnesium including most all of their alloys.When used on these metals it works easier and has its greatest strength. HTS-735 II also works well on most other non-ferrous metals with the exception of stainless steel. Because non-ferrous metals all have different melting temperatures we have outlined these metals below and their different instructions. Remember the thicker and larger the piece of metal to be welded the more heat it will require, in contrast the smaller or thinner the metal, the less heat required.
General Information On Aluminum
Follow these three easy steps and you will create a strong, perfect weld every time.
Step One: Clean the area with a file, grinder, or wire brush in order to remove any paint, dirt, or oxidation. This 2nd generation welding rod does not require a special brush to make it work.
Step Two: Heat the working surface not the rod until the work surface is hot enough to melt the rod, just as if you were soldering or brazing. DO NOT PUT THE ROD IN THE FLAME . The pore structure of the metal to be welded must be opened with heat in order for the rod to penetrate the work surface. Check the surface temperature of the aluminium by striking the rod across the surface (just as if you were striking a match). You will not see a color change when heating the aluminium so check the temperature frequently.
The tinning process: Once the base metal melts the HTS-735 II rod, rub the rod briskly across the surface
(as if running a crayon across a hot skillet) this breaks up the surface tension between the rod and the base metal and creates a strong bond.
Step Three: When the weld is completed always allow it to cool naturally back to room temperature.
Pot Metal, White Metal, and Galvanized Metal
These are all zinc based metals, and all melt at approximately the same temperature as the HTS-735 II rod. When items are made out of pot metal and white metal they are typically poured into a mold. When working with these items, in order to retain their shape, it's best to place the pieces in a moist box of sand, or a piece of clay. This acts as your mold. Work directly in the flame without preheating the work surface. Pot metal and white metal will sometimes take a little longer to reach their melting points than the HTS-735 II rod just because they represent a larger volume of metal than the rod does. On galvanized metal heat the rod at the same time, but because galvanization is actually a zinc coating and is very thin it will tend to melt a moment before the rod. So once the rod begins to melt start regulating your heat to avoid scorching the galvanization. Before attempting to repair expensive or antique parts spend some time practicing on similar types of metal or pieces.
Copper and Brass
Copper and brass are denser metals than aluminium, therefore it takes more heat to open the pore structure of these metals.
Step One: Clean the base metal with a file, sandpaper, or wire brush. There is no need for a flux or acid with HTS-735 II rod.
Step Two: Heat the area to be repaired. Begin checking the temperature by striking the rod across the surface. Once you can leave a fine streak of rod on the surface pull the rod back from the heat and continue adding heat to the surface until this test streak starts to disappear. When this happens this is the point of penetration when the pore structure of the metal is open and a strong bond will occur. Be sure you continue to heat the metal until you see signs of penetration.
Step Three: Allow to cool slowly back to room temperature. NOTE: on copper water lines it may be necessary to use a heat stop to prevent heat transfers to surrounding areas. (see heat stops below)
Oily, Greasy, Dirty, or Contaminated Metals
When a part or metal has to be repaired has come in contact with oil, grease, dirt or a liquid contaminant there are special cleaning instructions. No matter how clean you get the work surface to begin with when you add heat to the base metal you will begin to cook the foreign material out of it. The best way to work on these types of metals is to clean them. When adding heat you will see the surface begin to turn black or discolor as the contamination or carbon comes to the surface, at this point remove the heat and clean. You may have to repeat this (heat/clean/heat) several times until the Carbon or contamination quits rising to the surface.
Vertical and Overhead Repairs
Normally on overhead and vertical repairs you are unable to apply as much rod to the work surface as if you were working on a flat surface. So start out by tinning the surface with a small amount of rod and allow it to cool slightly. Then come back and build up your weld by softening the rod in the flame then laying it on the tinned area and then bringing that area up to 700°f. When the rod reaches a liquid state it has a great deal of surface tension to it and attaches bak to itself rather easily. Vertical repairs can easily be done by alternating the rod and the heat and starting at the bottom and stacking the weld on top of the tinned area.
Cracks, Thick Pieces, and Castings
Propane works well on thicknesses up to 1/4". On heavier pieces or to save time oxegen acetelyne is acceptable. Always make sure you have the torch adjusted to a clean burning flame. A rosebud tip is recommended. Cracks should be V'ed out through thhe thickness of the metal. Preheat the surrounding area to be repaired to 500°f. Heat immediate area and tin. The desired thickness and strength can be achieved by softening the rod and applying to the tinned area and bringing the temperature up to the melting point of 700°
Joining Pieces and Lapping
Often two pieces of different thicknesses are difficult to join together using regular brazing techniques. Try this method: Tin both peices seperately. After tinning position or clamp both pieces together and reheat. Once the tinned area reaches 700° the rod will attach back to itself (it's just like glue with heat). This is a great way to put a large patch on a boat or a piece of irrigation pipe. On Larger patches roll the on like a sticker start heating at one end and pressing down as you go. Holes up to 3/8" can be bridged entirely using TS-735 II rod.
Heat Stops
When you have work that is close to another repair in is a good idea to use a 'heat stop'. This can prevent older work from being seperated. There are several comercial heat stops available. You can also use a wet rag, mud, clay or for smaller aplications paste-type toothpaste.
Thread Replacements
Stripped out threads can be easily repaired by using either of two methods.
Method One:Drill out old threads oversized about 1/8". If the hole is open on the bottom, seal off using steel wool or other steel (such as a coffee can lid). Place a good quality black steel bolt in the hole. Begin heating until both the bolt and the basemetal are hot enough to melt the rod. Push the rod down around the bolt until slightly overfilled. Position the bolt for alignment and allow to cool. When cool, break the bolt loose with a wrench and remove. This method will not work on small bolts simply because of the torque necessary to remove the bolt.
Method Two: (This method is preferred). Drill out the old threads, not necessarily oversized. Seal off, as in method one and heat base metal until hot enough to melt the rod into the hole and fill. Allow to cool, file until smooth. Center punch, redrill and tap. This second method gives a superior set of threads and is reccomended in most applications.
Spark Plug Threads
Clean thouroughly with rotary file or brush. Using oxygen acetylene, heat the area around the hole, wipe inside of the clean hole with HTS-735 II rod until a layer that is equivalent in thickness to the missing threads has been obtained. Use a thread chaser to establish new threads when cool. be sure to turn engine over a number of times with plug missing to exaust any debris.
Filling a Large Hole
Start with a clean area, tin the entire inside of the hole. Now clamp a piece of steel to the backside of the hole. Once the hole as been tinned you can work right in the flame with the rod you are merely adding rod to the existing rod and this can be done at 700°. When the hole is full allow to cool and machine til smooth. also to save the rod, try cutting a patch for the inside of the hole.
Propeller Repairs
On rough edges begin by clamping a piece of steel on the back side, tin the edge of the blade and begin to build up to desired size and thickness. After the prop cools machine to size and place on bearing or nail. The heavy blade will tip down some take of some of this blade, or add to the other blade to achieve balance.
Trouble Shooting
There are only three reasons why HTS-735 II rod will not bond to the surface it is aplied too.
- The nuber one mistake most people make when first using the rod DO NOT PUT THE ROD IN THE FLAME . The rod will tend to melt before the base metal is hot enough to bond with it.
- When the base metal becomes hot enough to melt the rod you must RUB THE ROD BRISKLY INTO THE SURFACE IN ORDER TO BREAK UP THE SURFACE TENSION BETWEEN THE ROD AND THE BASE METAL.
- If you are unable to make a sufficient bond, it has to be a carbon or contamination problem TRY THE HEATING AND CLEANING PROCESS AGAIN.
- Make sure you are working with non-ferrous metal IF A MAGNET DOESN'T STICK TO IT YOU CAN FIX IT. (the exception to this is stainless steel)
If you have a question about a specific repair feel free to send us an email
and we will do our best to help you out.