.75 MDF, what size/type of screws to use?

[sqhertz 5,000+ posts]

titebond is the brandname. there is a titbond 1 and III but II proved to be better.

elmers probond is popular on here also.

 

[disturbedfuel15 10+ year member]

http://www.caraudio.com/forum/showthread.php?t=176424

 

[o6blink 10+ year member]

IF you don't have clamps, and don't want to purchase clamps (me), what screws do I need for the job? Would screwing or nailing be better? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[PV Audio 5,000+ posts]

Okay people, screws are not a replacement for clamps, let alone glue. You lay down your glue, clamp it tightly, then screw the wood together to hold the clamped bond while you go about your other business on the box. Otherwise, you won't get a chemical bond and will only have a strong physical bond.

 

[406er 10+ year member]

glue, clamp, air nail for me

 

[jmanpc 5,000+ posts]

i use 1 5/8"

 

[helotaxi 5,000+ posts]

Okay people, screws are not a replacement for clamps, let alone glue. You lay down your glue, clamp it tightly, then screw the wood together to hold the clamped bond while you go about your other business on the box. Otherwise, you won't get a chemical bond and will only have a strong physical bond.

If you predrill the screws prior to aplying the glue you don't need clamps. I've built tons of boxes without using the first clamp by screwing it all together. The screws provide the clamping force to give the glue the best potential for a good bond.

There is no chemical bond in wood glue. The wood is not fused together like styrene plastic is when using plasti-weld. The glue does soak into the wood and integrate the wood itself into the final resin matrix, but that constitutes a good mechanical bond, not a chemical one.

 

[PV Audio 5,000+ posts]

Wood glue doesn't make a chemical bond..? I'm going to need to see some proof of that because not only have I heard nothing less than wood glue making a chemical bond, but my grandfather owned a woodworking mill and told me that wood glue makes chemical bonds, and he was in the business for about 50 years.

 

[helotaxi 5,000+ posts]

Wood glue doesn't make a chemical bond..? I'm going to need to see some proof of that because not only have I heard nothing less than wood glue making a chemical bond, but my grandfather owned a woodworking mill and told me that wood glue makes chemical bonds, and he was in the business for about 50 years.

Chemically bond what to what? Wood glue soaks into the wood and then hardens. It is designed for porous materials becuase the fact that it soaks in is vital to the joint strength. It has a low adhesion compared to something like epoxy which uses the strenth of the adhesive bond to make a strong joint. In a proper wood glue joint, the result is a composite joint. The glue is the binder and the wood itself is the matrix. The result is something akin to a layup of fiberglass where the resin is integral to the finished product, but that is still completely different than a chemical bond.

 

[PV Audio 5,000+ posts]

From what I've been told, wood glue emulsifies the woodfibers at said joint and bonds the pieces together. This is why it's nearly impossible to directly shear a wood glue joint apart when it's fully set. It holds true for other glues, but you'll just keep tearing the wood shorter and shorter and the glue won't actually separate. I'm sorry as well though, because I'm very ignorant when it comes to things I've been told, so if you are in fact right, then I learned something new today. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[PV Audio 5,000+ posts]

And the "soaking in" reasoning doesn't really work very well because cyanoacrylate glues do the exact same thing, but they aren't designed for porous materials...

 

[05fronty 5,000+ posts]

whats titbond 1 and 3?

 

[o6blink 10+ year member]

titebond I is like the first kind..first strength. II is the second strength. III is their toughest/strongest glue.

 

[PV Audio 5,000+ posts]

But titebond 3 is worthless to box builders because unless you like waiting weeks for your glue to fully cure OR you are going to be swimming with the enclosure, you're wasting your money. I seriously dropped about a teaspoon of T3 into a clump of sawdust, and it took over four days to dry. That's retarded. Titebond 1 is fine, but T2 is like 50 cents more, so you minus well buy it. I'm currently using ProBond, but it seems like they switched up the formula or something, it has a consistency like titebond 2...which I don't particularly like (great glue, too runny. the old probond was thicker and set better for workability).

 

[o6blink 10+ year member]

At the lowes near me they had all three types for the same price.