Skeeter_ca
Should i clean up the image before converting them or fix the ones already converted.
The tiff lines are OK as are most raster files. The main raster clean up that you might want to do before converting is to erase cross hatching, the grain, and remove any black filled areas (just leaving its outline) before converting to DFX.
Fix the broken lines in CAD then you should be able to thicken the lines. I have been using raster to vectors for about 12 years now and none of them will convert to DXF without you having to do some reconstruction. Almost all of my model CAD files started out life as a scanned raster file. I usually do a complete reconstruction.
Gene