Loctite or JB Weld

[Gordon]

I am in the process of inserting a combustion cylinder into a mounting base block. This is for an Adkinson Differential engine. I will be installing a 1.2" OD x 1.125 ID x 5 3/4 lg DOM tube into a 2" x 1 3/4" x 3 1/4 long block. Intake, exhaust and spark plug ports are through the block and into the cylinder. The joint must be air tight and not move once in place. My plan is to insert this cylinder with a fairly tight slip fit into the block and coat this with JB Weld. My question is whether this will work and if Loctite would be better?

Input welcome.
Gordon

 

[doc1955]

I personally would go with Loctite.

 

[stevehuckss396]

I'm with Doc. Use the green penetrating type loctite. I think it's 290

 

[TonyM]

Loctite 1158514 Head Bolt and Water Jacket Sealant

 

[davidyat]

I've used some Loctite 609 with their primer when the Jacobs taper keyless chuck was slipping in the R8 adapter I was using. So far no slipping at all.
Grasshopper

 

[Gordon]

One of the problems I have with Loctite is knowing which one to use. There are all kinds of thread blockers available but I am not trying to retain a bolt. I have some 609 and some 660. In reading the specs it looks like the 660 would be good. My results in the past have not been very good. I have never used primer. Perhaps I should.
Gordon

 

[WOB]

When there is a large contact area, most any of the anaerobic adhesives will work. For hobby use, the main difference between the different types is viscosity and ultimate shear strength. I have used Loctite 609 with out primer many times on all kinds of applications with no problems. It is a low viscosity liquid and will fill up any available space by capillary action. With aluminum alloy 6061 and steel surfaces, no primer is needed. Primer can be used and will speed up the curing process, but it is expensive. I have used the primer when the metals in question required it, but the need is uncommon in my experience. The Loctite website gives guidance on which metals require primer.

Loctite 290 is very useful to the hobbyist since it can be applied to assembled fasteners as well as slip fits. I suspect it is basically identical to 609, but marketed towards different users. The various colored thread lockers will also work to strengthen a press/slip fit provided the available air space can be filled. With all of the anaerobics, heating will accelerate the cure tremendously. A brief blast with a heat gun or a torch will do the trick, just keep the joint temp below 250 degF to be safe.

WOB

 

[Gordon]

Thanks. I have both 609 and 290. I will probably go with the 609 since the 290 is listed as a thread blocker.

 

[doc1955]

I find Loctite sets up nicely if you clean parts that are getting locked is to clean well with some denatured alcohol. Yes primer will speed it up but I seldom use primer.

 

[Gordon]

It is done with 609 so now wait and see.

 

[Wizard69]

One of the problems I have with Loctite is knowing which one to use. There are all kinds of thread blockers available but I am not trying to retain a bolt. I have some 609 and some 660. In reading the specs it looks like the 660 would be good. My results in the past have not been very good. I have never used primer. Perhaps I should.
Gordon

Hi Gordon;
Not being an engine expert here I'm going to suggest 609. I've used this stuff extensively at work on servo drives, high speed packaging systems and other beasts that take a lot of beating. The problem is Loctite has hundreds of sealant / adhesive options some that may be better than others, all I do know is that 609 work like a champ for the applications I've used it in.

So this has me wondering how is it not working well for you? You need to follow the instructions paying special attention to cleaning. I like to use a good degreaser followed up by using a no residue electronic contact cleaner. Then apply the Loctite and primer as directed. In simple terms the surfaces have to be clean of anything that might act as a release agent. Do remember though that 609 has a specific usable range that I believe maxes out at 5 thousands of an inch. Also keep an eye on the recommended temperature operating range of the product.

I haven't made use of some of the other recommendations such as the Head Bolt sealant that TonyM mentioned. It just goes to show that there are many possibilities and this is just from Loctite/Henkle.

 

[Wizard69]

I find Loctite sets up nicely if you clean parts that are getting locked is to clean well with some denatured alcohol. Yes primer will speed it up but I seldom use primer.

Clean is very important. It might seem silly to repeat this but it is the key to getting most sealants, tapes and glues to work correctly.

 

[kquiggle]

Some useful links to glue "guides" here (look under "Adhesives and Glueing"):

https://sites.google.com/site/lagadoacademy/useful-links#info-other

 

[bobden72]

Just to add to the list when I needed some retainer for my cylinder liners on my Edwards 5 I contacted Loctite and they recommended 620 or 638. They are both cylindrical retainers and are both high temperature resistant up to 200 deg C. I fitted my liners no primer just a clean with some thinners I had knocking around, all went OK and no problems.

 

[Gordon]

The 609 seems to be working just fine at this point. I have other problems with the engine but that has nothing to do with attaching the cylinder to the block.

 

[chrsbrbnk]

I would use 620 the high temp and gap filling we used it for years in gluing bushings in to lamination plates subject to heat something like 360 to 380 deg. F

 

[Lloyd-ss]

Generally, the color is the indicator of the strength of the cured Loctite, but each color comes in several viscosites, from thin as water to thick as 90wt oil. Green (strongest), then red, then blue. The mil spec versions of the Loctites are the same as stuff we can buy but it uses letters (A for green, C for blue) and "V" after that for thickness/viscosity. Grade A is the thin, but strong, green (like 290), followed by AV, and AVV (like 680 cylindrical locking compound). Go by the color to judge the strength, and the viscosity based on the gap you are trying to fill. Also remember that a heat gun is often the preferred way to break loose a cured Loctite joint. So, beware of high temp applications. But Loctite does have lockers for high temp.

Primers are necessary when bonding non-reactive metals (stainless, titanium, etc) but not really needed for active metals (ones that corrode or rust easlily, like bare aluminum and steel.) But cleaning and lightly sanding to expose raw metal will improve the final strength. For example, Loctite bonds better to sanded aluminum than to anodized aluminum. Also, using a Primer will speed the cure of a joint very noticeably, no mater what metal is being bonded.

Personally, I don't get too concerned about the expiration dates, but I do periodically make some test pieces to verify strength. I have noticed it taking longer to cure as it gets older, but it is too expensive to just throw away. I'd be gone if that were the case, too! LOL.

 

[Technical Ted]

I would use 620 the high temp and gap filling we used it for years in gluing bushings in to lamination plates subject to heat something like 360 to 380 deg. F

I used 620 as well instead of soldering the internal parts for the Stirling 60 I made. I've run it over an hour now with no issues. A lot easier than soldering IMO.

Ted

 

[josodl1953]

I've got Loctite studlock ( green) ,it's over 30 years old, still works fine . Amazing stuff....
Jos