PDA

View Full Version : Welding Advice



Hornet - n/a
1-Oct-08, 06:27 AM
I want to weld a crack in my engine frame. Can I leave the engine mounted to the frame when I do this? Or will this cause some type of damage to the electrics such as magneto, CDI unit etc. Engine is a Robin EC44.

hovmart - n/a
1-Oct-08, 06:31 AM
just unplug the cdi unit should be ok

ScotsSpeed - n/a
1-Oct-08, 12:16 PM
also if battery fitted disconnect. Protect fuel lines.

jon_curtis - n/a
1-Oct-08, 12:38 PM
do the above, but ask your self why has it cracked?



just welding up a crack in steel is a big no no. if it failed due to fatigue then you will further weeken the structre close to the weld, causing further cracks to openin the heat effected zone of the welding. it will fail again close to the original crack.



Hope i am not telling you how to suck eggs, but dont just weld up a crack, make the structure stronger with gusset plates etc, in the area of failure.

hover t - n/a
1-Oct-08, 09:04 PM
Got to agree with jon

welding a crack work hardens the steel and results in a larger crack next time plate it aswell

Remember to disconnect any earth straps as you dont want to put a positive charge into anything electrical on the craft



Trev

profqwerty - n/a
2-Oct-08, 01:01 AM
Are you welding it in the craft? If so something to protect the fibreglass from molten blobs is good like a piece of wood http://hovercraft.org.uk/images/icons/smiley_icons/icon_smile.gif

Hornet - n/a
2-Oct-08, 05:09 AM
Thanks to everyone for the reply's. Yes I was thinking of welding the frame in the craft but was not sure if this may damage anything electrical. If it is I will remove the engine from the frame.



I understand what you are saying Jon, with regards to welding a crack. The frame was cracked in other places and I did reinforce all the areas I repaired but I missed this particular crack and only noticed it after the craft was back together and had been out for a couple of runs.

martyn_bannister - n/a
5-Oct-08, 08:00 AM
Hi,



on top of all the rest - 2 things occur to me



Have the welder earth clamp as close to the welding site as possible to limit high current to the path between the two.



Fibreglass does burn so fire precautions!



Rgds,