No. 4"A" Reproducer loose isolator gasket

[Mitchell_5898]

-Reposting my question from another board

Almost finished rebuilding my 4"A" pot metal reproducer. Only problem I am currently having is that the new isolator flange gasket I bought is sitting loose and just a little proud of the throat. Now I'm not sure if it sitting a little proud is an issue, but it sitting loose in the throat has me concerned I am going to get air leakage, plus now half the time when I'm adjusting the reproducer to "drop the needle" the reproducer comes off my tone arm. As in, the reproducer comes off and the gasket is still sitting on the tone arm, and the screws are left in their holes. It almost feels like the rubber is too soft and gives too much for the screws to hold it securely in place. Has anyone had this issue before? Ive tightened the set screws more but it seems to have little effect. Any help would be appreciated, I really don't want to spend another 25 bucks on another flange.

The gasket in question, I bought off ebay from Gettysburg Antique Phonograph

[Inigo]

photos of the reproducer, gasket etc in this status would be most illustrative to understand your problem...

[Phono48]

As in, the reproducer comes off and the gasket is still sitting on the tone arm, and the screws are left in their holes. It almost feels like the rubber is too soft and gives too much for the screws to hold it securely in place.

Which holes are the screws left in, the gasket or the reproducer?

Barry

[JerryVan]

Since you reposted your question, I'll repost my answer...

I have used black silicone sealant to fill the gap and seal the isolator rubber. Be sure everything is located properly before allowing the sealant to set.

[JerryVan]

As in, the reproducer comes off and the gasket is still sitting on the tone arm, and the screws are left in their holes. It almost feels like the rubber is too soft and gives too much for the screws to hold it securely in place.

Which holes are the screws left in, the gasket or the reproducer?

Barry

If I may, I believe he's saying that in use, the reproducer falls off of the rubber isolator in spite of the setscrews still being in place within the reproducer neck.

[Inigo]

You fortunates can understand what he's saying, or maybe in this other site you've seen photos of what is he referring to with these 'gasket' 'screws' etc..
I imagine he refers to the backplate and its neck rubber joint to the tonearm, which may be loose... If this is it, I can say (just two cents for providing some help, if its useful), or at least to understand the problem and give moral support...
European HMV no4 soundboxes, similar to the VIctor ones, had a rubber joint in black with a brass insert solidly attached to the rubber at the factory, when casting the rubber. This ring set (rubber + brass ring) was intruduced in the backplate neck or throat, and fixed with
- one small screw downwards, a simple point that sets into a small cup practicated in the rubber surface,
- one screw with a long pin that goes through the rubber and brass ring, protruding inside the neck, to fix the angular position of the soundbox in the tonearm, as it goes into an L shaped runway in the tonearm. This fixes the angle of the needle on the record, the famous 55º-60º angle.

In European HMVs, first models of no4 had the rubber flush with the soundbox throat. Later editions used to protrude 2-3mm out of the throat, forming a ring around the tonearm. Besides that, this outer rubber ring was past the inner brass insert, and so had smaller inner diameter, so it firmly grip the tonearm making a better leaktight joint, so this is desirable.
These tend to get hard and loose with the years.
I've cast my own rubber joints 'in situ', using the brass insert as internal mould and the soundbox throat as external mould, and it more or less works. But the best replacement I've found in terms of functionality (for HMV no4/no5 soundboxes) is the red rubber rings that colleague chunnybh sells in eBay (or here if you PM him) and now I believe others also provide. Those are made for the EMG and Meltrope soundboxes, but fit inside the no4/no5 soundbox throat perfectly tight, and also around the tonearm, with no need for the brass insert. Advantages: several.
1) They are flexible and provide leaktight joints and very good sound
2) As there is no need for a brass insert and the screws, the rotation angle of the soundbox in the tonearm is free to be modified, it is maintained only because of the rubber grip around the tonearm ---> tracking angle can be better adjusted
3) there are sizes for the narrow and thick bore tonearms of HMV. Probably they also fit equally on the Victor tonearms and soundboxes (Exhibition/no2/no4 and for the orthophonic).

[Mitchell_5898]

Sorry everyone for the delayed response, I have been busy the past few days. But to clear up any confusion, I am talking about the rubber piece with the brass insert that holds the reproducer to the tone arm. Ive seen people call that part many different names so i wasnt exactly sure for the right word to use. I seen the recommendation for black silicone sealant, which I think I will try. Will any do, or any preference on brand? The main issue I was running into was that the screws that hold the reproducer on, weren't seeming like they wanted to do their job of holding the reproducer securely to the rubber insert. I'm thinking that silicone recommendation might end up doing the trick. I've also thought of wrapping the rubber in electrical tape to increase the outer diameter.