Mixing HHG & LHG

T

TripH

Member
New member, please excuse if asked-answered or posted in wrong area...

Typically use HHG+10% urea for joinery and LHG if more open time required... Keep a plastic jar of HHG and small bottle of OBG in the pot and just grab what I need...

Applying moldings over the weekend and ran out of urea. I like the quick grab of HHG for moldings, so prefer HHG over LHG for that application, but needed a bit more open time than HHG alone... So mixed 50:50 HHG(192)+LHG(old brown) and cooked it down a bit... Seemed to work fine: got some grab plus reasonable open time... Any reason to avoid a mix? Any ratios to recommend or avoid? Any reason not to drop urea all together and just add LHG to my HHG as needed? One less thing in the shop... One less variable -- always a good thing...

Thanks.
h
 
Trip H,

Well I never thought of mixing the two.  I would say Patrick Edwards is the best person to answer this question. I would say Old Brown Glue is the best option from all the options available for Liquid Hide Glue (LHG).  I personally enjoy have both. When I need fast tack or hammer veneering than Hot Hide Glue (HHG) is the best. When I need open time than LHG is my choice. 

I am not sure if this helped in anyway, but I hate not seeing a response.

Cheers,

FR
 
Thanks for a reply...

I usually have both OBG and HHG in the pot at the same time and just grab a squeeze bottle based on desired properties --- fast tack vs long open time... If I want a tack+open time, I extend the HHG w/ urea... The mixing idea was just a one off to get a fast tack + extended open time when I ran out of urea -- needs being a mother and all that...

I'll eMail Patrick for input -- thanks for the suggestion...

I've got nothing against HHG+U, but if a dash of LHG does the same thing, why stock urea?

 
It is good to keep in mind that not all hide glue is the same. Different gram strengths have different properties. Lower gram strengths have longer open times than higher gram strengths.
 
I've got 192 and 251 in the shop... I tend to keep 192 in the pot for simplicity's sake and cook it to adjust the properties... If I'm going to rub-joint some panels, I'll either cook-down the 192 and/or add some 251... If I'm assembling drawers, then I'll add some urea... So what's in the pot can be a bit of a chemistry experiment. I just go with it and make it work... If I'm veneering, I've got a separate bottle of 192 without adulteration... So adding some OBG to the HHG was just another ingredient for my general purpose 192 brew... At the beginning of every project, I clean the pot and start again... Not all that scientific, and probably not best practice, but it seems to work...
 
Received feedback from Patrick...

HHG(192) & OBG are chemically equivalent, so mixing is AOK...

I’m looking at HHG as the baseline adhesive and seeking desired handling properties with modifiers and cooking. Patrick looks at OBG as the baseline adhesive (go figure) and recommends against modification – as viscosity is carefully formulated...

When I use OBG, I’m looking for longer open time, so really don’t play with the mix – other than keeping it warm... So I don’t adulterate my OBG... Thanks Patrick...

I’ll defer reordering urea and play with mixing OBG into my HHG as the need arises... I’ll keep experimenting until something goes wrong... For now, adding OBJ to HHG(192) extends open time while leaving me with the quick grab that I like for moldings...

For my builds, I'm generally looking to extend open times... I've never used 315, but imagine it sets-up right quick. I find even 251 pushes my assemblies into a high-blood-pressure zone... I'm always looking to extend things unless I really need a super-fast grab (glue-blocks, mitered feet, panel rub joint, etc), then I just cook-down the pot.

Anyway, learned something new -- and that's always a good thing...

Thanks all.
 
OMG Your discussion needs 200 plus years to see what works. Hyde glue is very brittle cross grain but reversible. I have no answer to an alternative. Old dog rule. Use what you are used too!
 
==>Your discussion needs 200 plus years to see what works
Assuming folks will want to keep what I build in 200 years... Not quite to that build-level... Yet... :)
 
I did not mean any disrespect. Your family will cherish all you have made. Pieces we make today will be someone's treasure tomorrow. That is the best glue.
 
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