I am getting ready to start a trailer project and ran across this forum a few days ago. I am impressed at both the talent and patients here. Good group of people.

I am familiar with both Stick and Mig welding and have done both. I am no where proficient with either but seem to get the job done in a hobby/ad-hoc fashion.

The trailer project I am starting is a smaller 10x5 #3500 axle utility trailer. Main use for hauling camping supplies with a utility shell atop.

It will be constructed with 2 x 3 x 3/16 angle.

The machines I have available to me are:

Mig - Dayton 90/110 amp ac/dc
Stick - Miller dialarc 250 ac/dc

My primary question is what kind of Joint would be recommended for this project?

Mitered butt joint, lap joint or a coped joint. Maybe this is a matter of taste, but I would like to make sure that there is not a structural reason for each type before I discount them.

On a side question, or maybe it has to do with the type of joint used, I would like to use the Mig as it seems to be easier but I don't seem to be getting good penetration on clean metal (3/16"). I am using flux-core wire. Does shield-gas wire get better penetration?

It is harder for me to see what I am doing (can't see the joint with an auto darkening #10) but I read in other threads that I will probably need a stronger work light and use one of those white weld pencils to mark the joints and

I hope what I am asking makes sense. I really want to do a good job since I will be pulling a trailer down the road and would rather not have the thing fall apart on the first (or umpteenth) bump.

Thanks for any advice.

I forgot to mention that the joints I asked about are for the bed frame corners. Forgot that only my Wife could read my mind (intentions).