Fill Rat holes/Weld Access Holes????

Date 07-16-2010 15:10 Edited 07-16-2010 16:44

eekpod
It depends what you want it to look like or do, (wadded up toilet paper stuffed in, Bondo utilized sanded smooth and painted, wind and moisture proof).
I got this from AISC Site
Weld access holes should not be filled with weld metal -- doing so could create the very same cracking problems the weld access hole was used to prevent. If the hole is to be filled for appearance reasons in architecturally exposed structural steel (AESS), it is possible to use a body filler such as "Bondo". Refer to Section 10.4.1 of the AISC Code of Standard Practice (a free download from www.aisc.org/code.)
Good Luck
Marshall

10.4.1. The Erector shall use special care in unloading, handling and erecting the
Structural Steel to avoid marking or distorting the Structural Steel. Care shall
also be taken to minimize damage to any shop paint. If temporary braces or
erection clips are used, care shall be taken to avoid the creation of unsightly
surfaces upon removal. Tack welds shall be ground smooth and holes shall be
filled with weld metal or body solder and smoothed by grinding or filing. The
Erector shall plan and execute all operations in such a manner that the close fit
and neat appearance of the structure will not be impaired.

By CHGuilford (****)

Date 07-16-2010 16:23

This has been on the forum before. Marshall is correct, those should not be filled with weld. Automotive body filler (Bondo) is commonly used to fill the holes and it holds up very well.

The trouble is that welds and Bondo don't go together in the same sentence without someone jumping to the wrong conclusion.
Many will ask what happens if the Bondo falls out? (I don't know but it seems to stay stuck on cars that move around a lot.) Others will ask if paint will stick to it. (Gee, I dunno - seems like it will; body work gets painted so I think structural steel wouldn't be much different.)

Point is: an RFI to the customer will prevent a lot of issues later. But don't be surprised when the engineer tells you to fill the hole with weld anyway - happens all the time.

By eekpod

Date 07-16-2010 17:44

Chet, yes I agree they tell us to weld them even though its not supposed to be like that.
I didn't take into account that my parts are galvanized so I can't bondo them, I'll have to weld them, ug.
thanks anyway.

By DaveBoyer (*****)

Date 07-17-2010 02:52

If You end up using a bondo type filler, keep in mind that they are not all the same. Some use a gypsum base filler, and can absorb water, others use fillers that don't.

They are generally pollyester base adhesives, in case You need to know that when coating/painting.

How do You patch / restore the galvanized surface after welding?

Back when We painted cars, We had an etching solution [galva-prep] to be used on galvanised steel to prep for paint.