Re: EMD F7 (MDM Locomotive Works Kit) starting on sides
Posted: Mon Jun 12, 2017 12:59 pm
by cbrew
Hi John, hows it going?
if it was me. I would weld them on from the back side using plug welds, this way it does not distort the visible sheet metal.
if this is not an option, you can use a high quality adhesive like loctite 330 https://www.mcmaster.com/#7560a54/=181f8yn
its not cheap but it will hold.
or you can rivet the sheets on
Brew
Re: EMD F7 (MDM Locomotive Works Kit) starting on sides
Posted: Wed Jun 14, 2017 8:11 am
by johngraser
I have been having a hard time finding someone to do the welding on it. It is looking like I'll probably have to go adhesive.
Chris, haven't been doing much on my locomotive, due to some of the instruction are not to clear.
The live steam club here in Saint Louis had a major flood about a month ago so we been trying to get the track back to a runable condition.
It's looking like next summer we will be moving back to Oregon.
John
Re: EMD F7 (MDM Locomotive Works Kit) starting on sides
Posted: Fri Jun 16, 2017 11:17 am
by cbrew
OK, with out the proper setup and skill, one can burn throw the sheet metal so the adhesive is probably the best move.
well if you do end up moving back, it will be good to have you back.
Re: EMD F7 (MDM Locomotive Works Kit) starting on sides
Posted: Sun Jun 18, 2017 12:53 am
by Steggy
johngraser wrote:I have been having a hard time finding someone to do the welding on it. It is looking like I'll probably have to go adhesive.
If you are going to use adhesive to assemble the body you must be meticulous with cleaning and prepping the joint.
I've got a lot of experience joining steel to steel and steel to other materials using thixotropic paste epoxies, such as PC-7. What I have done for many years is start by scuffing the mating surfaces with 3M Roloc medium abrasives (you need a small, high-speed angle grinder), air-blasting to blow away the grit from the scuffing operation, followed by thoroughly cleaning the mating surfaces with acetone, using a lintless cloth (cloth baby diapers work). I then mix and apply the epoxy as soon as possible after cleaning, and clamp as necessary. Epoxies cure more quickly if some heat is applied, so if you can, work outdoors on a sunny day for some free heat.
That's really all there is to it.
Incidentally, PC-7 is much stronger than the structural adhesive MDM was recommending. I used it to build up the body on my race car, and also to join the nose casting to the rest of the body on my F7.
Re: EMD F7 (MDM Locomotive Works Kit) starting on sides
Posted: Fri Aug 18, 2017 8:06 am
by johngraser
Here is a video of the progress on the door frames: