[cboy]

I bought interior spray adhesive in bulk and intend to shoot it through an old siphon gun. But a number of questions arise.

1) How should I clean the gun? This project will take me a LONG time...so I don't think I ought to just leave the gun with residue in it as suggested in this thread http://www.hotrodders.com/forum/spraying-contact-151086.html?highlight=adhesive+clean

2) Can the adhesive left in the pot be returned to the bottle for use later?

3) How long can the adhesive sit in the gun before set up problems arise?

4) I want to shoot most of the adhesive out in my shop, rather than in the house, because of the fumes. What should shop temps be both for spraying and for best adhesion.

 

[302 Z28]

Depends on the adhesive. It's never a good idea to leave adhesive in the gun for an extended period of time. I have however left DAP Landau Top adhesive in an old Harbor freight gravity feed gun for a week while I was doing my interior and it stayed spray-able. I found about the only thing that would clean it was Xylol. Paint thinner and lacquer thinner just balled up the adhesive and made a mess out of it. FWIW, I tried spraying the DAP out of a new cheap siphon gun and it would not flow. I had to switch to the gravity feed gun.

Vince

 

[NEW INTERIORS]

I left some in my gun up to 25 days with no problem..As long as you keep it closed.

 

[snkbyt]

I have used a suction gun for years. I use a cheap primer gun from Harbor Freight. In the last 5 yrs I've never had to clean the gun just the tip sometimes with laquer thinner. I spray at about 40# pressure. I have used both the special foam type glues and now using the Weldwood Vinyl top glue on my interiors. Don't worry at all about the gun and don't empty or clean it just keep the gun for glue. The gluse doesn't harden in the can and it doesn't in the gun. Good luck.

 

[Jon]

Our existing wiki article on this topic, Contact adhesive, doesn't address these specific questions. But, I'm posting it here in the hopes that, when these questions are answered, someone (possibly me) will update the article.

 

[DanTwoLakes]

Snkbyt is exactly right except for the lacquer thinner. The solvent for the glue is mineral spirits or xylene. Xylene works faster, but it is a lot more expensive. DO NOT THIN CONTACT ADHESIVE. If it 's not spraying right it's your gun, not the glue. I leave DAP Weldwood top and trim adhesive in my Harbor Freight gun # 43760 and never clean it. This is an HVLP gun with a 2.0MM nozzle. You need at least a 1.8MM nozzle or it won't spray right. The secret is to get a gun that is external mix. In other words, the glue and air are mixed just outside the nozzle. Now I will grant you that I probably use it up faster than you will, but I have let the gun sit for 2 or 3 months without using it with various amounts left in it and it always fires right up. It may take 20 seconds to get going, but it will still spray. DAP needs to be at or around 70 degrees to spray properly. The glue works better when it is not humid out because it takes forever to dry when it's humid. Once you pour it out of the original container, don't pour it back in. Leave it in the cup or pour it out. Also, contact adhesive is not going to spray smoothly like paint. It looks like a pebble finish when sprayed correctly. Contact adhesive can be re-activated after it has dried too long by simply spraying on another coat.

 

[snkbyt]

Looks answered..

 

[DanTwoLakes]

Snkbyt: I just got an e-mail wondering where your answer went.

I don't know what happened to it, but I want you to know that the moderators have the power to remove your answer and replace it with something else, but would never do that. Sam (One More Time) and I, are the only moderators in this forum. If your answer somehow disappeared it did not happen because of any of his or my actions unless it was some kind of an accident. I have not looked at the board since 4:00 p.m., so it couldn't have been me. If I would have done something like that, I would not have mentioned your first answer in my answer.

 

[cboy]

Thanks for all the great info guys. Looks like it will just be a matter of finding out if this old gun of mine has a large enough tip to shoot the glue properly.