Hi MrM1,
I have a little bit of “catching up” to do with this topic 
[quote]So lets talk seams … Regardless of what you read or are told by a salesman, especially if you are a “Princess and the Pea” type personality (and admittedly I am) … You WILL FEEL A GLUED SEAM in the comfort layer of a cal king bed.
If you purchase a cal king (and i would guess a king too) and it is not split into 2 parts at each layer … In other words the comfort layer is 1 continuous piece … If purchased from Mattressses247 There will be a glue seam off center of the bed. I was told talalay latex is not manufactured in a cal king width so it has to be glue seam constructed. If i recall my discussion with Mattresses247 correctly, they take 2 extra long/large twins and cut off enough from one of them to make the width a cal king. Then using the pieces cut off, they use those pieces to add the 4" of extra length to make a cal king … Gluing all the pieces together. So u will have 2 seams. One offset/ off center down the middle and One 4 inches off the bottom or top depending on your rotation.
I have no idea if this is true, but it has been my experience. The way Mattresses247 explained it to me, when they glue a seam, the glue used will seep in about 2 inches or so either side of the seam and that this is part of the bonding of seam for talalay latex. I did do tests of just the 3" soft glued comfort layer laid out in my living room floor. Taking an 8 pound dumb bell, a 4 foot level and measuring tape, when I placed the dumbbell where we each sleep … The dumbbell sunk in exactly 1/2 of an inch more where our bodies lay than it did on the seam. AND this was consistent from top to bottom along the seam so it does not appear to be just brake in. The seam IS MORE FIRM…!!! There will be a 4-5" patch down the off center of the bed that is (for me) noticeably more firm. It gives me the sensation of laying on a small hump in the off center middle of the bed.
I do not think this is a fault of mattresses247 … Just the nature of seamed latex … But i could be wrong.[/quote]
When a manufacturer glues a seam it is generally glued with the full 6" core and then the layers are slit afterwards so they are glued on the sides not on the top. In the large majority of cases the glue seam is undetectable but on occasion they can use too much glue or overspray or otherwise do a sloppy job with gluing or in some cases with a king size they may not do the best job in “matching” one twin XL to the other and there could be a slight difference in firmness between each side that may be noticeable. If there is a layer in a mattress where the glue seam is as noticeable as your experience seems to indicate then I would consider it to be defective rather than being a “normal” experience because a glue seam is something that you “shouldn’t” be able to feel.
[quote]Here is where I need help and suggestions. I am visibly seeing body impressions where we lay when the bed is assembled… These are not getting any worse over the past 20 days and noticed them in the first week we had the bed. But I CANNOT visibly see the body impressions when the comfort layer is laid out in the floor by itself. Yet the seam is verifiably more firm when laid on the floor. Oddly all the other pieces are level and consistent by themselves. I have tried various rotations with the comfort layer … And the “Rise” is the seam. It switches sides of the bed when i rotate (the seam is off center)
Here’s the problem … when i lay across the bed at a 45* angle, with part of me on one side and sinking in … and the lower part of my legs on the other side not sinking in as much, the seam intersects my legs just between my hips and my knees when laying on my side … And everything from the knees down kinda floats just above the layer not sinking in because of the firmness of the seam. When laying on my side … This causes knee pain.[/quote]
I’m not sure why there are visible impressions that you can see on the mattress that aren’t visible when you lay the layers on the floor but it could be connected to the seam that is firmer (which could be “raised” a little). It could also be connected to your cover if you have a quilted cover which can compress in the areas that you sleep faster than the areas that aren’t used as much and it could also be connected to the support system under the mattress because a “dip” in the support system or areas of the foundation that are more flexible than others can “travel through” the mattress and this is a possibility with the foundation that you have which has flexible slats with two center support beams that are rigid.
If you are feeling the seam that much then it’s also quite possible or even “likely” that you would still feel it to some degree “through” a very soft 2" 15 ILD topper because you could still be compressing the layer below the topper enough to feel it but I don’t know if it would be enough to modify the feel of the ridge “enough” that you don’t feel it at all. The topper also shouldn’t have a noticeable “seam” that you can feel.
I would tend to sleep on the combination that is closest to your ideal (and if they are close then on the firmer of the two configurations) for a few weeks so that the mattress has a chance to break in and you have a chance to adjust to the feel of a new mattress. You may also find that a rigid foundation may “firm up” the softer of the two combinations so it was more suitable for you (you could test this on the floor). There are also some suggestions in post #2 here that may be helpful with a new mattress that is too firm.
If none of the other suggestions work well to get to your “ideal” layering then after a month or so (which I think has already passed) then I would consider adding a softer topper to “fine tune” the mattress a little more. If you do decide to go in this direction then post #2 here and the topper guidelines it links to can help you use your sleeping experience to help you choose the thickness and firmness of the topper that would have the best chance of success. It also includes a link to the better sources for raw latex layers or latex toppers that I’m aware of in any thickness or firmness that you would prefer.
I hope I’ve covered all your questions but if I’ve missed any in my reading let me know
Phoenix