Weld up holes in frame or not?

[70Chevy4x4Nut]

Need your opinions on whether I should weld up half dozen holes I will not be using. After reading where welding on the frame is critical, I may just leave them alone. What would you do?

[Senor_paco]

Leave them be. You can actually weaken the frame due to the heat from welding, and sometimes strategically placed holes can strengthen the frame.

[TooMany2count]

then explain to me why so many people weld the holes close on thier frames & box them.. as for weakinging it this may be true IF you had a large consentration of heat in only one area, BUT as lot of folks know many of the car & smaller truck frames were welded from the factory. SOOOO personally I'd say go ahead & do it, as long as you have so idea what you're doing. I have in the past & will continue to weld up the holes in my frames & box them it need be......joe

[68LSS1]

Weld it, box it, channel it, chop it, drop it......sorry, get carried away. Weld them up. They will be fine.

[smokekiki]

I drove and worked on heavy trucks.They all had a warning about welding on the flanges.We filled holes in the web all the time.These where trucks that where used,and where also shown.When we welded on the flanges,to lenthen the frame,we fish plated behind it.

[Krosati]

Welding the holes shouldn't be a problem. Even the factory recomend welding fissures and fractures in the frame. Keep the heat localized (MIG orTIG) do not use oxy/act

[70Chevy4x4Nut]

Thanks for all the comments. Now I need to just go out and do it.

[COBALT]

The first thing I did with my trailing arms once they were off the truck is have them welded up. Any weakness you'd get by heating and cooling will be greatly overcome by the added strength of the modified member.

Also a word about holes in steel that are subject to torsion, tension, and compression:

These forces translate to stress and can lead to deformity, especially when cyclic loading is the cause (bending a paperclip back and forth until it breaks - or for our trucks starting, stopping, bumps in the road, etc.). When a member is subject to these forces any holes in the member will develop stress concentrations around the hole. This is where the highest concentration is, where usually the stress is evenly distributed depending on cross sectional area. That's why cracking, ovaling, and displacement can take place resulting in ill-fitting new brackets that should fit but don't and require opening the holes, or relocation.

Therefore, it's probably a good practice to weld the holes up if you know you'll never use them. Another way to deal with it is to thread the hole and install a plug, or install a tight-fitting bolt of the same steel grade. That's probably your most versatile option, but more time consuming and more expensive.