I have a 1950 3100 that I just purchased and it has a gap between the front fender and the cab , its about a 8 inch area from the top to about 8 inches down the back , is there anyway to correct this ? Its tight every where else , I have been told that this is a common problem. any help would be appreciated .
I'm not sure this is the problem you are addressing without a picture,but there is a fender welt strip that fills this area. Look at this and see if its what you need. Sorry the pic is a Ford LOL Attachments: https://talk.classicparts.com/images/attachments/4429643a0258bb56.jpg
Thanks for the advice , that is the problem but I didnt want to use the fender welt because it would stick out like a sore thumb on my bright orange truck
Here are a couple of ways we work with a problem like you have. If it's already painted go to an upholstery shop and have them make you some welt in a matching color. They all have a "welt foot" for their sewing machines that can make welt in various diameters on the round roll part. 3/16 to 1/4 will cover most regular gaps but wider can be made if necessary. If not painted, put some Saran Wrap on the body where the fender will bolt up to it and "butter" the fender flange with a generous helping of filler then, while still soft, pull the fender to the body with the fender flange bolts. It's best to have the fender in position with longer than normal bolts that you can back off enough to let you smear the filler in place. After it sets you can trim the excess and sand to contour. There is a lot of tricks to gets that perfect gap look you see on these old trucks because they sure didn't come that way from the factory. Coachwork just wasn't a priorty because these trucks were sold as WORK trucks when new and as long as they kept you dry when it rained and reasonably warm in the winter, they did their job.
When I assembled my freshly painted 54 3100,I could see daylight between the cab and the front fenders much as you describe. I had used welting, so you had to get under the fender to see any light. I used black silicon caulk from underneath. Once i sealed the crack,and blocked the light, the gap really hid itself.