These are my thoughts on my questions. I’m not an expert and as always if you read something I wrote do your own fact checking never take my word for anything. I’m the definition of an armchair internet prick sitting in the peanut gallery but I will always try to be helpful and share what I believe to be true.
If it’s unknown mild steels, high-strength steels, ultra-high-strength steels do we assume at least (HSS) and proceed with best practices for that?
I will almost always assume at least HHS and preheat and cover after to help cool slowly, I don’t go out of my way with temp-sticks or follow a defined procedure other than getting some heat in it first then covering with a glove or something like that.
Pre heat and post heat always or not needed. If no pre heat should the moisture be chased out of the parent material before welding, if yes only acetylene or is propane okay?
Like I said above yes I like to preheat and I’ll chase the moisture line out as my indicator as to how much heat I have, I use propane but I’ve been told the moisture in propane will create issues in your weld and not a good source of heat for preheat.
Fish plates, needed or not needed. If needed when are they needed?
I like the Idea but I don’t do a lot of fish plating unless I feel the extra strength is needed like a previous repair failed and I’m stacking a weld over an existing weld or a complete frame section being added.
Supporting the area to be welded, needed or not needed. If needed what’s the best practice for a guy at home?
I feel like this is important if you don’t have the ability to check and adjust straightness after the fact and believe you are starting with a straight frame, I have two methods I use here in my home shop. I have three 2’X4’X3/8” plates I can bolt to the floor then use 2” and 3” adjustable tubes tack welded to the plates and frame (like cheap jack stands) to bolt the frame to the floor. I’ll do whatever work I do then cut the tacks from the frame, if the frame still lays flat on all 6 or more points that it was supported on before the work was preformed then I assume it’s still straight and move on, if not I address the issue while the (jig) is still setup. That is a pain in the butt to setup and to be honest I haven’t done it in a while but I do have several chunks of large I beam and I use them all the time to support something while welding and it’s the same process of scrap steel welded for bracing kind of thing. A dedicated frame jig or table would be fantastic but not in the cards for me space wise for the amount of that type work I do.
Welding start and stop locations, matter our not. If it matters what do we need to consider when planning out our weld strategy?
I’ve never given it much thought but
@Cruisers and Co was talking about wrapping his welds and now has me thinking more about this.
Drilling holes and random spots on a crack repair, needed or not. If needed where do we put them?
I’ve always drilled a hole at the end of the crack because that’s what I was told to do and I’ve never questioned its effectiveness, I’ve also heard drill a hole every inch but I haven’t done that. Another thought I’ve had that would be interesting to hear what the experts say is if an automotive frame cracks not from an impact then it’s likely work hardened in that area. Would you address that with some annealing, extra fish plating beyond the area?
Vertical welding yes or no. If yes up or down, any special precautions?
I know it’s unavoidable but I try to keep it to a minimum and will make something on a diagonal at the very least if possible, I’ve always heard vertical up is the preferred method but very seldom do it and to be honest I haven’t given it much thought until we started talking about it here. I would come up with a secondary doubler plate or a different design all together if I have to put several vertical passes in a short span (I don’t have any facts to back this up but it FEELS wrong to have mutable vertical passes all together on an automotive frame)
Don’t judge me on spelling and grammar this morning it’s been a long couple days and I tried to bang this out quickly.
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