Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: propman on August 21, 2021, 02:15:25 pm

Title: Welding on to chassis
Post by: propman on August 21, 2021, 02:15:25 pm
Is there any particular precautions to take before welding anything on to the Foretravel chassis? Such as disconnecting batteries or unplugging electronics, if any?
Few years ago for our previous 94FT I had paid someone to replace the old muffler with a resonator. As best I recall, he had used very minimal welding, just for one hanger.
This time I am thinking about removing the old muffler from our current 03FT myself and installing a resonator. The way the muffler is installed on ours does not get the bedroom hot, but it is big/ugly and I know a resonator be slightly better.
I can weld and prefer to weld couple of hangers for the new pipe and resonator. What should I be aware before I weld anything on to chassis or should I not?
Thank you,
Al
Title: Re: Welding on to chassis
Post by: len.barron on August 21, 2021, 02:40:02 pm
Is there any particular precautions to take before welding anything on to the Foretravel chassis? Such as disconnecting batteries or unplugging electronics, if any?
Few years ago for our previous 94FT I had paid someone to replace the old muffler with a resonator. As best I recall, he had used very minimal welding, just for one hanger.
This time I am thinking about removing the old muffler from our current 03FT myself and installing a resonator. The way the muffler is installed on ours does not get the bedroom hot, but it is big/ugly and I know a resonator be slightly better.
I can weld and prefer to weld couple of hangers for the new pipe and resonator. What should I be aware before I weld anything on to chassis or should I not?
Thank you,
Al
make sure and clean the surface you put your ground clamp to bare metal and keep that ground within 3ft of where you are welding...no other requirements...I do a lot of auto fab work and the only time I'll disconnect an electronic item is if it's in between where I'm welding and where I'm grounded or I'll remove it altogether if it is in the heat affected zone..
Title: Re: Welding on to chassis
Post by: bbeane on August 21, 2021, 02:41:49 pm
At the very least, remove the chassis's and house battery cables, and keep your ground as close to the work as possible
Title: Re: Welding on to chassis
Post by: dsd on August 21, 2021, 03:17:48 pm
Welding checklist (https://www.foreforums.com/index.php?topic=42522.msg426079#msg426079)
But
I do disconnect and ground out the positive cables for both sets of batteries. Ground clamp close to work area and recommend not using hi frequency aluminum work on coach. Does weird  crazy stuff, similar to static discharge events. Just my opinion for my own work.
Scott
Title: Re: Welding on to chassis
Post by: len.barron on August 21, 2021, 03:30:34 pm
I installed battery disconnect switches for both house and chassis for battery life/preservation...more by default than anything they are probably in the off position when I weld on the coach...but...I weld on my rockcrawler all the time and never think a second thing about disconnecting batteries..


A/C Tig is another animal altogether...to the greatest extent possible you want to do that work on a bench..
Title: Re: Welding on to chassis
Post by: propman on August 21, 2021, 03:57:15 pm
Humm, I just found this:
"Disconnect the following before welding on completed coaches:

U270/U280/U295 - B-21 - Alternator ground at alternator
C-2 - Transmission ground at breakerboard
Allison ECU - Under dash / driver's side / both plugs
ABS - 3 plugs in brake ECU - Power in / Front axle / Rear axle
HWH -All grounds on coach and engine batteries
U240 All of the above except ABS
U300/U320 C-E18 Same as U270/U280/U295 plus:
PEEC-ECM at engine - lower square plug w/ allen head screw (2402)
U300/U320 C-E22 Same as U270/U280/U295 plus:
CELECT-ECM at engine - top plug w/ 2 screws (38459) and round Deutsch plug (2348)
Any coach with Aqua Hot option:
Disconnect A9 red 8 ga and A10 black 8 ga at breakerboard in compartment
Any coach with Primus option:
Unplug all connections on boilers
Disconnect #8 black at control panel inside coach"

I may just use clamp/bolt on hanger and not weld at this rate :-)
Title: Re: Welding on to chassis
Post by: Barry & Cindy on August 21, 2021, 04:49:51 pm
For resonator hangers, you may find other strong fasteners other than welding.
Title: Re: Welding on to chassis
Post by: Dub on August 21, 2021, 04:57:19 pm
Humm, I just found this:
"Disconnect the following before welding on completed coaches:

U270/U280/U295 - B-21 - Alternator ground at alternator
C-2 - Transmission ground at breakerboard
Allison ECU - Under dash / driver's side / both plugs
ABS - 3 plugs in brake ECU - Power in / Front axle / Rear axle
HWH -All grounds on coach and engine batteries
U240 All of the above except ABS
U300/U320 C-E18 Same as U270/U280/U295 plus:
PEEC-ECM at engine - lower square plug w/ allen head screw (2402)
U300/U320 C-E22 Same as U270/U280/U295 plus:
CELECT-ECM at engine - top plug w/ 2 screws (38459) and round Deutsch plug (2348)
Any coach with Aqua Hot option:
Disconnect A9 red 8 ga and A10 black 8 ga at breakerboard in compartment
Any coach with Primus option:
Unplug all connections on boilers
Disconnect #8 black at control panel inside coach"

I may just use clamp/bolt on hanger and not weld at this rate :-)
A cuss word comes to mind followed by I wonder if that's enough.
Title: Re: Welding on to chassis
Post by: oldguy on August 21, 2021, 05:15:07 pm
I weld by putting the ground right beside where welding and I only use DC welders.
Title: Re: Welding on to chassis
Post by: Pierce & Gaylie Stewart on August 22, 2021, 11:58:36 am
I do the same as OldGuy putting the ground next to what I'm welding. I have a Miller wire feed. I'm not sure it's the smartest but has worked for me. Could be expensive if it fried the ECU so I'm not making a recommendation, just what I do.

Pierce
Title: Re: Welding on to chassis
Post by: Protech Racing on August 23, 2021, 02:26:27 pm
I disconnect the batteries and any ECU that I can find.
  I dont think that my bus has any..