Pioneer chainsaws

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Pioneer issued a Welding Data Service bulletin #PB-83-Aluminum and Magnesium. Pioneer added the letter "M" behind the casting part
number (cast in)to identify all Magnesium die cast pieces. Parts without the letter "M" are aluminum.

The recommended procedures for welding a casting after identifying the alloy are given here.
 
lnfo is from Pioneer Saws : Welding Magnisium

Recommended: Eutec Rod made by Eutectic welding alloys , their are two types magnesium welding rods each with a matching flux.

1. No.1900 - ldentified by an orange tip- used for repairing breaks, cracks, building up missing parts and filling porous castings. it can be used with either oxy-acetylene or oxy-hydrogen torch. Flux used-No.1900

2. No. 1902 - ldentified bya grey tip. this rod has the same uses as the No. 1900 rod and can also be used with both types of torchs. Flux used-No.1902. this EutecRod No.1902 is preferred by Pioneer welders. lt has a lower flow temperature and is , therefore, not apt to result in a porous weld.

Procedure - for both No.1900 and No. 1902 are same

Remove dirt, scale and grease from joint area. Bevel broken section to form a 75 degree - 90 dgree "V". Preheat area to approximately 400 degree F. and either sprinkle area with flux or heat rod and dip in flux and transferit to joint. Heat until flux melts. Melt off a drop of the rod and flow it out. Add more Rod, Keeping it in front of the torch which has its flame cone about 1/2" away from the base metal.

Caution - 1. Use a gentle flame
2. Do not overheat base metal. Apply as low base heat as possible, as rod does not require fusion of surface of base metal.
3. lf possible , " back up" small section when welding.
 
I think I saw it in a post on some rod DSS was sending you.

ahhhh, that's a while ago... it hasn't got here yet. bbb gave me some, used w/good results on his 395 cases. you'll hafta hit him up for pics. I didn't get any.

Just curious, how/were you able to fix it?

grind alum off. redo w/mag rod.

@Beavers ive never gas welded either, but would like to try. only done tig. aka heliarc.
 
The i.d. is 3.5" The original is a fairbanks morse 7/16-7 .063. It's worn out . Was thinking of joining a new rim style to my old drum and going with 404 .
 
I bet a home machinist would remachine that spur to the 404 dimensions?
For a 4600 mac I plan on machining a spline to convert to rim...... clutch drums are near unobtanium in 2.735" i.d.
For yours tho there is likely enough meat to 'convert' to 404 pitch....
Just thinking out loud haha
 
ahhhh, that's a while ago... it hasn't got here yet. bbb gave me some, used w/good results on his 395 cases. you'll hafta hit him up for pics. I didn't get any.



grind alum off. redo w/mag rod.

@Beavers ive never gas welded either, but would like to try. only done tig. aka heliarc.


Alluminum The recommended rod is a 1/8" diameter low silicon content 9 5 per cent )aluminum rod The universal spec for this rod is S-33.
Aluminum brazing flux is preferred, however, Albox Aluminum Flux and various other manufactures types may be used with equally satisfactory results. The flux should be mixed with a small quantiyy of water and used in paste form.
The flame should be neutral with a slightly carbiurizing cone.
The oxygen pressure gauge setting should be approximately 15-20 psi and the acetylene 5-7 psi.

Procedure:
The casting should be removed from the machine and the area to be welded thoroughly cleaned and scrapped down to a clean new metal surface. Any dirt or oil left on the surface to be welded will oxidize during the welding and prevent the rod from bonding with the parent metal.
The casting should be pre-heated and the actual welding should move fairly rapidly to eliminate puddling and overheating of the weld.
After the weld is complete remove all traces of the flux. if it is not washed off it will cause rapid oxidation and deterioration of the metal around the weld.

Brian
 
I bet a home machinist would remachine that spur to the 404 dimensions?
For a 4600 mac I plan on machining a spline to convert to rim...... clutch drums are near unobtanium in 2.735" i.d.
For yours tho there is likely enough meat to 'convert' to 404 pitch....
Just thinking out loud haha

That thought has been discussed. And after measuring it's to worn . But the drum is good . IMG_1530.JPG
 
I met with the guy about the pioneer 600 and we made a deal for 3 saws. The 600 poped off with a prime so thats good . Compression feels good, really old gas in it. The 20" hard nose and chain are shot The clutch was stuck (or so I thought). I took it off and noticed no springs and this washer in between the drum and clutch .When the nut is tight the clutch/drum are bound together. What should it look like?
Tom



IMG_1532.JPG IMG_1531.JPG
 
Back
Top