Help requested with Mole Richardson Baby 751

Joshua Ian Parisi · September 27, 2016

Hey everyone,

I recently purchased a mole baby 751 from ebay. I cant seem to find any information regarding the light however online. I called mole on the phone and they said its the same light as the 407. My problem is that there does not seem to be any way to keep the fresnel lens locked in place. Theres a small clip that goes towards the lens, but it does not keep the lens secure in place in the slightest. Is there a piece that is potentially missing to keep it, or am I missing something?

Gregg MacPherson · September 27, 2016

If you swing the lens open and took a pic on both sides someone might spot the problem. There is a file of 407 parts drawings you can download that may help. Try on the MR site. Let me know if no luck. The old ones originally came with an aesbestos cussion around the lens, aesbestos in or under the bulb socket and maybe some of the internal wiring. That can all be safely removed I read.

There's a chap in Illinois who refubishes old lights like this. You can visit him for a day, help in the shop and he teaches you how to. This lead is from about 2012. Read the posts by "ship".

https://www.controlbooth.com/threads/reconditioning-407-412-substitute-part-questions.29974/

Alex Nelson · September 27, 2016

I have an old Bardwell McAlister 2k that had a similar problem. The pinch ring that they used to hold the fresnel in place had a thick asbestos insulation around it that actually made contact with the glass. Most of it had deteriorated or rotted off by time I got it, meaning there was no longer enough pressure to keep everything secured. I carefully removed the rest of the asbestos and wrapped gaff tape around the metal ring instead, as a temporary replacement. I don't know for certain if the 751 had the same asbestos wrap, but it could account for the loose fresnel.

Gregg MacPherson · September 28, 2016

Hey alex,

I nosed into this because I have a couple of MR Baby Solar Spot 407s that are very old and I'm sure still have the aesbestos cushion for the lens. That seems sound, though it's going to be replaced with glass fibre if I get around to refurbishing them. Braided glass fibre rope, or various sections with a braded sheath, should be available from other industries if MR don't have or are too expensive. For example, log burners use a braded glass rope to seal the firebox.

When I got those lights they were running photo floods. I converted one to a 650W tungsten with a modern (1980s) bulb socket, an aluminium riser to get the bulb centred on the reflector. This was in the late 80s.

There may be strict rules on the removal of the aesbestos. With some research you could find a safe DIY way, but you need to be carefull.

EDIT: One way to keep safe from airbourne aesbestos is to wet it down. Work in an environment with a lot of wet surfaces.

Edited September 28, 2016 by Gregg MacPherson

JD Hartman · September 28, 2016

EDIT: One way to keep safe from airbourne aesbestos is to wet it down. Work in an environment with a lot of wet surfaces.

Generally correct. Bag and seal up any removed Asbestos. Wash down any surfaces that may have come into contact with the fibers during the working life of the lamp. More info on Asbestos abatement can be found on Controlbooth dot com. Search the site, don't ask....

Alex Nelson · September 28, 2016

Sorry, I should definitely have stressed the safe removal aspect of the process more.

JD Hartman · September 28, 2016

Generally speaking, you shouldn't be doing it at all. A theater, rental house etc. would be sending the heads to be cleaned up by a company with proper containment and disposal facilities. The head really should really be totally washed out with a detergent and water solution as there are certainly fibers which have found their way all over. A good time to repaint the head inside and out, the baffles, replace the socket if necessary and replace all the hardware with the equivalent in stainless.