Wood never stops moving. Forty-one-year-old lacquer likes to crack. Don May's 21" (53.3 cm) long Co-Hog Lola T70 MK IIIB body was created using jelutong wood and painted in Sunoco blue lacquer. A complete restoration is well under way.
In 1982, when the Co-Hog T70 was built, there was little reference material available other than the photos Don provided. Now there is a plethora of, photos, specifications, and stories. They help me make subtle adjustments to my original forms.
Steady progress is being made on refining the upper bodywork. Truly flat acrylic sanding blocks, much better sandpapers and films, and a few intervening decades of experience are leading to much better results.
The starting point for all the rework is the bottom surface. It must be flat for all other surfaces to flow up from there.
The gray areas are already flat, and the green arrows indicate the troughs that are still too low.
It took a considerable amount of sanding to keep everything even across both surfaces. All sanding was done by hand, since power tools could quickly be overkill in such a delicate situation. Adding filler would have just made the original problems reoccur even faster.
The bottom was finally true. The edges of the surfaces could then be used to guide shaping of the body contours as they roll up and around the sides, front and rear surfaces.
This helps refine the body masses and lines for more accuracy and symmetry.
Based on the new reference materials the front fenders will be tapered inward toward the centerline and the cabin profile has changed slightly.
The multitude of rear details will take significant time to clean up.
I decided that trying to fix the original wheel rims and tires would lead to results that would not be up to the standards of the rest of the restoration, so I'm making new ones.
New reference materials also led to better wheel and tire interpretations. CAD models and drawings were done to carefully map out the new details. There will also be a turning jig needed to reverse the tires accurately and match the outside and inside profiles during turning.
I'm hoping the wheel centers will only require minor modifications and fixes. Each knockoff is made up of four pieces and removing them will be quite a painstaking task.
To help them stay true longer, a plank of aged, shop stable, clear poplar was selected as the base material for the tires. Enough material was cut for three fronts and three rears. It's better to have some extra.
The original wheel rims and tires were one piece. They were turned from a laminated block of poplar. Replacement tires will be turned from laminated blocks of clear, shop-acclimated, vintage poplar.
New, separate wheel rims will be turned from sections of inherently stable 2 1/2" (6.35 cm) diameter acrylic rod.
Rear tires will be turned from a lamination of three layers. The fronts require two.
Each layer was carefully matched with adjacent layers during cutting to keep the wood as similar as possible to reduce future movement. The middle layers were flipped before glue-up to minimize concentric cupping forces.
Existing cupping was removed by thickness sanding each layer. The bottom of each piece was thinned by 0.007" (0.18 mm) and the top by 0.003" (0.07 mm).
After being laminated they were squared up on the disc sander and most of the extra material was removed with the bandsaw.
All turning will be done on my 45-year-old Sherline lathe. It has served me well and with replacement components, has gotten better as my abilities have expanded.
Manual digital measuring devices have added a great deal to accuracy. I do have direct reading electronic read out equipment for the X and Y axes, just haven't seen the need to install them yet considering current excellent results.
If you missed, it check out the introduction post for the restoration.
See you again when there's more progress to report.
Previous Lola T70 posts: