Durability of Contact Cement?

[John Stevens]

I'm about to start a project that involves laminating a two-ply, wood-over-wood veneer to a chipboard-type substrate. There would be some advantages to using contact cement as the adhesive. The alternative would be PVA adhesive (can't use epoxy, resourcinol or other formaldehyde adhesives for this particular project).

The only concern I have is whether contact cement will hold up over time, or will it tend to lose its grip sooner than PVA adhesives?

Thanks in advance for any help you can give me.

[Mark Singer]

I have had good luck with it. I use wax paper and work from the center out. Apply to both sides and let it dry. Use a roller and a block rapped in a towel.

[Bobby Nicks]

I've not had very good luck with contact cement. Have had a couple of things fail after 7 - 8 years. For the short term it has held pretty good. Both items that failed were veneer over a plywood substrate. It's always possible that I did something wrong when I intially used it, but if that was true I don't think it would have took 8 years for it to fail.


Bob

[Lou Morrissette]

John,
I had a similar experience that Bobby had after about six years. It was formica over mdf on the fence for my router table. I was using it one day and it just popped off. I must admit that it was the first failure that I've ever experienced and I've been using contact cement for many years on various materials.

Lou

[Chris DeHut]

Hi John,

I am not a big fan of it due to the probability of failure. Most of the failures I have seen with it are when thin veneers (wood) are applied to a substrate, then finished with a solvent based product. Thin veneer will allow the solvents to pass through it, thus causing problems with the contact cements.

I have been working with some water based contact cements of late, but I just don't have enough history with them to know if they work for the "Long haul".

If you have a vacuum press (or other type of veneer press), you could use liquid hide glue. PVA glues are generally not the best choice for veneer work as there could be problems with what is commonly referred to as "Creep". I have also found that if the veneer is thin, bleed through is a major problem when it comes to finishing. There is an adhesive by titebond called "Cold press" glue which is a PVA glue with solids added to prevent bleed through. With my limitted experience using it, I can't say for sure if it is good or not.

That's about all I can think of at the moment.

Chris

[Mike Holbrook]

I have used contact cement in water craft for many years. My experience has been that it is great when it works, but it can be difficult to use. You can end up with a big problem if the two sides touch in the wrong place.

I have also found that like resins it can be hard to judge how long to wait before attempting to join the two parts. Temperature and humidity can effect drying time pretty dramatically. If the two sides are to wet or to dry you do not get the best results.

I would suggest doing a small test glue up each time you use it to make sure you get your timing correct.

[Sam Blasco]

In my experience contact cement and paper backed or thin veneer do not go well together for a few reasons. Chief among them being air pockets and "booger" lumps. It is extremely difficult to get the veneer to lie perfectly flat to the substrate. A thin veneer will show every imperfection (it is also why plywood generally doesn't make for a good substrate here). Contact cement is also very unforgiving with zero open time. You can get away with a heat gun for some fixes with plastic laminates, or a solvent, but forget that with veneer. Also, as mentioned earlier, solvent based finishes can prove problematic.

Now, I believe you said you were going to use wood on wood, two ply veneer. This is an instance where contact cement will prove very effective. That under layer of wood practically elimiates the chief problem. This is also true of phenolic backed veneers. Contact cement, if done properly is very durable, and will stand the test of time, as long as it is sealed properly and not exposed to extreme elements. One step that I have found that most woodworkers leave out is scraping. That is, after the laminate is just past tacky and ready to bond, take a scraper (a 12" paint edger works nicely here) and scrape both surfaces to reduce bubbles and help even out any inconsistencies. To help with lay up a judicious bunch of "sissy sticks" (3/4" strips of 1/4" ply or wood, or dowels) about every six inches between the two surfaces to be bonded help tremendously. "Sissy Sticks" on the substrate, laminate on the "Sissy Sticks" and when you have it where you want it start pulling out the sticks from the center and work your way out. Also when you start rolling (a wood or plastic burnisher will work better than a roller with veneer) press from the center/inside to out, then press the edges tight.

Hope this helps.

[John Stevens]

Now, I believe you said you were going to use wood on wood, two ply veneer. [snip] That under layer of wood practically elimiates the chief problem. [snip] To help with lay up a judicious bunch of "sissy sticks" (3/4" strips of 1/4" ply or wood, or dowels) about every six inches between the two surfaces to be bonded help tremendously.

Sam, thanks for all that info. Coupla dumb questions--

1. The "chief problem" you were referring to is the adhesive bleeding through the veneer and causing finishing problems?

2. Should the "sissy sticks" be waxed to facilitate removal?

[James Carmichael]

Well, I'm brand new to veneering, so I have no idea how long my stuff is going to hold up, but what about cold press glue?

[Wes Bischel]

John,
I've always used the extra slats from mini blinds for my "sissy sticks". As long as they don't have contact cement on them, they slide right out.

I have never used contact cement for veneer, but I have done my fair share of HP laminate.

Just remember to have good ventilation!

Wes

[Sam Blasco]

1. The "chief problem" you were referring to is the adhesive bleeding through the veneer and causing finishing problems?

2. Should the "sissy sticks" be waxed to facilitate removal?[/QUOTE]
The "Chief Problem" is any imperfection, dents, air pockets, air bubbles, glue"boogers", will show through thin veneers. Not so with WOW (wood on wood or phenolic backed).

My "sissy sticks" are 1/4" prefinished ply, never had a problem so I never waxed them. Couldn't hurt, I suppose. I have known others to use blind slats, and they work well, too.

[Mark J Bachler]

Yep what Sam said.

I used to use foil-backed veneer once in a while. Seemed like the solvent based finishes didn't bother it as much. I also used to scrape the contact cement & use sissy sticks. If I had large sheets to seam together I'd use wood glue back 1/2" on each side of the seam & tape across the veneer to pull it tight. Then clamp the seam down tight with a follower stick & clamps. This would help keep the seam from opening up in time. If you do get a small air bubble you can sometime suck the air out using a hypodermic needle, & then shoot wood glue back in & clamp it down.