Dunlavy SC-IVa speaker cabinet refinishing source?

My veneer specialist does not think the problem lies with the glue. He said that veneer does not expand, and that appears to be what has occurred relative to the MDF cabinet. He thinks it is a problem with the MDF substrate. I blame the glue, like Rja believes. [Rja, my edges have completely separated as well.] Upon receipt of the speakers when they were new, I noticed that the veneer had some water damage on some surfaces, so moisture may be a culprit at some level. It also may be a bad run of speakers that were affected. As I said before, my first pair of Dunlavy's were fine (SC-IV's). I have seen a pair of V's with the same veneer release problem that were owned by an investor group member for DAL in 1998-1999.

I discovered a website that discussed matters concerning veneer on MDF substrates. Moisture can be a problem, as well as the glue. Apparently, the best glue bond between MDF and veneer is obtained through applying two coats of glue to the MDF substrate. The first glue coating sort of seals the MDF substrate, while the second glue coating serves as the bonding agent with the veneer. I don't know the veracity of these statements, but it seems to make some sense given the nature of MDF material.

If one applies only one glue coating, then the glue can seep into the MDF material, resulting in less glue being available at the MDF-veneer interface for bonding. If an additional glue coating can provide an adequate seal for the MDF surface, then perhaps that coating prevents changes in the moisture content of the MDF material.

Anyway, I am having a local Chicago veneer shop put fresh veneer skin on my SC-IVa's next week.

My personal opinion is that this problem is due to poor quality contact cement, which I believe has already been mentioned. And because only a small number of speakers suffer from this problem it was probably a specific glue used during a specific time period. This is the probable culprit since so many speakers remain in perfect condition after so many years.
BTW: My SC-IVAs suffer from this same veneer separation problem although around the edges rather than the centers of the panels.
If I ever hear a solution that makes sense I'll give it a shot.

Dan,
It can't be from a lack of moisture. There is little or no moisture in the Los Angeles area. I have two pairs of SC-V's neither of which have shown any of the problems you mentioned. I have owned these for around 10+ years. The veneer is still as smooth as the day the Speakers were purchased and they have been moved 4 or 5 times, baked in the hot sun, subjected to air conditioning, dust, etc. I have seen many other Dunlavy's in the LA area, and all still look mint. If there is a moisture problem it must be from exposure to excessive moisture. I can imagine the MDF expanding due to moisture content and causing the veneer to crack. But this scenario would seem to require a heck of a lot of water in the air, steam or something similar. How will you avoid a repetition of this problem?

Oil your veneers seems nones does anymore. Veneer holds far better on birch ply but since MDF is so much cheaper thats what most manufacters use.

Thanks for your input(s). I have identified a suitable specialist through inquiries to a veneer supply house. In response to Commcat's surprise of not having heard of veneer problems with Dunlavy's speaker's, it is indeed quite common with Dunlavy's larger, floor-standing, speakers (SC-III, IV, V, and VI). There is even one thread at this site from several years ago that sought advice as to how to re-attach loose veneer to a larger Dunlavy speaker cabinet. In my experience, the problem is more common than not.

According to the person who I found, veneer detaches from its substrate due to the substrate changing size on one surface (he said the substrate becomes unbalanced). In the case of my Dunlavy SC-IVa's, the cabinet MDF board comprising the speaker outer walls apparently lost moisture and shrank on their outer surface and the veneer began to detach at the weakest glue bond points, thereby forming bubbles in the surface of the cabinet. The speaker could also acquire more moisture and increase in size. This would lead to the veener splitting on the MDF surface, leaving apparent gaps in the veneer.

This "unbalance" in the moisture content of the substrate (here again, we're talking about the Dunlavy MDF board cabinet walls) can be avoided by veneering both sides of the substrate. I suspect that Dunlavy did not do this double-sided veneering of the MDF materials before assembling the cabinets, because the speakers were available with different custom-ordered veneer skins. Perhaps Dunlavy did not worry about the moisture content of their MDF materials since they were assembling their speakers in a relatively low-humidity environment of Colorado. But I would expect that the veneer problem would be more evident with the larger speakers (surface expansion and contraction being highest along the longest dimension) and would be expected to vary to the extent that the speakers are used in an evironment whose relative humidity differs from that of Colorado.

A high end piano store in your area may have a piano/furniture repairman than can do this for you.

I owned a pair of SC-IV's earlier and had no problem with the veneer, but this pair was made from cabinets by DAL's original outside cabinet supplier. I obtained my second pair of SC-IV's (the ones I now own, SC-IVa's) after DAL moved their cabinet manufacturing and finishing work in house. Apparently, my pair had their veneer attached with a bad glue batch.

This Audiogon seller seems to have extra IV-a cabinets available;

http://www.audiogon.com/cgi-bin/cls.pl?spkrfull&1245566300&/Dunlavy-Audio-Labs-SC-4-A's-la

This is the first I have heard of problems with the veneer on Dunlavy's of any size.