Broke Frame !

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Alright guys my father has an 1988 yeah a 1988 1/2 ton Chevy 2 wd truck and the Frame has a crack in it..   The break is on the passengers side.   The frame is not broke off it just has a crack in it the bottem part of the channel is cracked..   My question is how to repair it ?My father knows a heavy equipment mechanic who says to get another piece of frame off another scrapped truck and grind it down to fit inside the frame on my dads truck and BOLT IT IN PLACE !!!!!     I disagree with this totally !!!!!!!     I feel the original crack should be welded to prevent it from cracking further  and then put a piece of Angled steel inside the frame rail to help support it (welding it in) !The heavy equipment mechanic feels that welding will weaken the frame I wonder how he thinks the frame was put together ????My feeling is that drilling the original weak frame to bolt another piece in isnt going to help things it would probably make things weaker !!!Well guys any tips or advice will be appreciated !Thanks
Reply:I think I read somewhere that the crack itself really shouldnt be welded but some metal should be welded over the crack on both sides, like a crack sandwich. Make the 2 pieces about 4" longer over the crack in either direction, by as tall as the frame and weld top and bottom but dont weld the ends of the piece, because that can weaken your "patch".
Reply:yeah, lenght-wise welds...use pretty thick plates:==========  if this is the frame length-wise from the side==========get two plates the same height and about 4-5 inches long....lay these plates against the side of the frame and weld the top and bottom length-wise to the frame rail.  This will allow for some stretch and flex in the frame and will hold it together without allowing the crack to expand further.  Depending on the amount of abuse the vehicle gets (4 wheel drive...off-road...road course racing...etc...) you may want to go with thicker steel and longer than 5 inches.
Reply:Its the bottem part of the channel that is cracked not the sides (its the side that gives the frame its strength)...   The thing that I dont want to see happen is the crack spread from the bottem of the channel up the side...    The truck is only used as a daily driver and for getting fire wood it isnt really given a hard time !    My question is how thick of steel should be used ?Thanks for the tips guys !
Reply:thickness...I would recommend 1/4 inch (going bigger is always better with a frame, I would rather over do it than have it crack completely later).
Reply:FearcityINC,Tell me you didn't say "crack sandwich"!!!!
Reply:I think you need to find the end of the crack and get it stopped, even if you drill a hole and plug weld that. Here's a suggestiom for what it's worth. I see where others have done similar. Clean it all up naturally to fit whatever process you use. Weld it from the inside side of the channel. Then from the outside you can gouge it out good in a typical 'V'. This way you can get any porosity as well as use the new weld as a backplate. Weld that up and grind smooth. Then for re-inforcement use a strap along the bottom flange. About 8 inches long, same width as the flange and taper the ends. You don't want a lateral weld/HAZ straight across the flange for a new crack to form along. Make the taper fairly long with a blunt end.
Reply:You definately ned to stop the crack from running any further. Drillling a hole and plugging it is teh best way to go. I would not weld the crack until the support plate (patch plate) is welded over the crack, and at that I may not weld the crack at all. 1/4 inch should suffice.  Remember to prep properly or the patch work will be done on vain.
Reply:For what its worth, and I've done a few of those, I'd take Sandy's method.
Reply:To be honest guys as far as cutting a "V" in the crack well the frame is pretty slight in these trucks !  I would say the steel in the frame is only about 1/8th of an inch thick.  Yeah I like Sandys idea.  Now all I gotta do is try and talk the old guy into doing it the right way instead of him going and doing it the way that mechanic told him to do it !Thanks Guys
Reply:Your old man got good advice.  No one listens to older people so weld on the frame and regularly check the site for further cracking.  You may be lucky.
Reply:i have welded a few  semi truck frames that were broke in half..or jsut needed lengthened with an engineers approval.....weld frame 100 percent...make a patch of equal or  thicker  material about  12 inches each side of weld and  drill a 3/4 hole 1 1/2 inch from the  end of the  patch  and another every 3 inches along the  top and  bottom edge  of  the  patch (also 11/2 inch from edge of patch....bolt with  3/4 high tensile bolts and torque to 300 footpounds..mar threads so they do not  loosen