waterproof glue for architectural trim
slykarma
| Posted in Construction Techniques on
Hi all, been a while since I posted here. Hope everyone is not too silly busy like most of the industry seems to be at present.
I have a residential customer who wants all their styrofoam stucco window detail removed and replaced with S4S fir 1×8 trim. Three of the windows have arched tops at 18″ radius. I did a quick layout and it would seem I can make each one in 4 segments of 1×10 biscuited together and glued, then scribe and cut correct inside and outside radius. My question is, what glue to use? It will need to be waterproof but also be sandable and have clear glue lines. The trims will all be a tung oil finish. Planning to use screws for fastening over the stucco and then cut plugs for the holes.
Thanks in advance,
Wally
Lignum est bonum.
Replies
Gorilla Glue
make the mating surfaces slightly miusted first. The polyurethene glues cure by moisture. Too dry a meeting surface will not bond well. The glue foams to fill minor voids and will sand easily when cured with a gluer line that, if visible, will mate the colour of the fir nicely.
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Caution..the Gorilla glue will NOT expand the biscuts. Only water soluble glue makes em fatten up.
I'd lean towards titebond 2..it's not water proof for submersion, buy dandy for signs and things that will get wet and dry out.
I think his way would be trouble some..all that endgrain joints..I'd stack the chunks so it's long grain to long grain and then cut the arcs.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
By misting first, you introduce moisture to the biscuits.
But wait! There's more, If you act now, I 'll thrown in the fact that the Gorilla itself will expand to fill the biscuiots tight.
besides, I primarily count on biscuits to provide alignment more than strength, although I know they increase the surface bond area available in a joint.
Agree that end grain gluing is not ideal, especially for exterior work. The expansion and contraction of the sections will work to break any glue bond there, but I think - my opinion only, that the Gorilla is a stronger bond for this one than the TitebondII
Epoxy might be better yet.
if these were to be painted, I would go with cutting them out of a single piece of Medex exterior grade MDF
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some minor disagreements Pif. The grorilla will expand but the foamy expansive is not structural, and tho' I also have misted, it takes a bit more than that to really get em tight (IMO)
I once made a cedar cover for a lightwell in a basement..used Resorcinal and biscuts..wrong..they did no good what so ever.
I have used gorilla glue since it first came out, and frankly it's not all that great..PL premium poly, is way better,with out the mess, and it is still useable once ya open it and reseal it. I bought 2 qt. bottles of GG when it was new (and less expensive) and damn if 1 didn't harden like a rock in the unopened container.
I know there are applications that GG is fantastic for, I just have stayed away from it when it's failings seemed to outweigh it's benefits for me..
We do agree wholly on the other aspect of bricklaid vs. endgrain, and I also would (if painted) use something else.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
I would use the new Tightbond 3... It IS waterproof they say.
If I chose Gorilla Glue, I would use 1/4" x 2" splines in appropriate dado's... My prefered method anyway.
I should have said, I'd use splines whatever glue I chose. It doesn't take much longer than using biscuits... and it way stronger. I pretty much only use biscuits for alignment when joining boards for a panel, table top and such. (of course, spline grain is oriented same way as boards)
--- BRICK
"They say that there is a fine line between genius and insanity. I like to color outside the lines...and then eat the crayons." ~ Me
Edited 6/12/2004 6:23 pm ET by Brick
you can have my 3wing slot cutter when ya pry it from my cold dead router..lol
Me too, biscuts are for breakfast
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Way good Point! Splines would have prevented most of the joint failures I have seen in work of this sort.
This is the first I have heard of TBIII, BTW
Time to research.
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I have seen adds for TBIII but it is not in a store near me.
I do like the PL premium . I don't reseal mine ,I let the squeezout harden and self seal. come back in a month or more pull out the PL plug and glue away . No muss no fuss. All the holding power of a spankin new tube .
Work must be slow if you can get by with lewtting a tube of PL premium sit around for that long!
;)
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Yep ,I have a couple of caulking guns so that I have one to use when the others are hiding. I also have a couple of other jobs to tend when not working on my house.
Someone mentioned Titebond II which is weather proof at about the same rate as exterior plywood. Titebond III is waterproof and is a better choice. Gorilla glue will work with biscuts but just like the glue itself, the biscuts need moisture. This will be fine if the lumber is green but if its dry then you'll need to wet it first. Not the biscuits, just the wood.
Sincerely;
The Tool Guy
I built this arbor four yrs ago and use polyurethane glue for the arch segments (2x6 redwood joined with biscuits). The glue lines are virtually invisible and (so far) the arches are as good as new - although a bit darker.
Nice!
Just out of curiousity, did you offset the various joints or are they aligned with all pieces cut from same patterns?
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They're aligned in the sense that each arch is identical. I made a pattern from luan doorskin and used it to mark out the arches. The arch blanks were made from three pieces of 1x8 redwood that were glued up with two #20 biscuits in each joint. Before I glued up the pieces, I laid them out and marked the arch so I could locate the biscuits completely within the arch. When the glue was dry, I scraped off the excess and cut the arches on the bandsaw.
If memory serves, I used Bordens polyurethane glue. I've used two or three brands over the years and they have all worked pretty well.
If you're interested, I can take some more pictures and (if I still have it) can post the drawings I made.
I guess the quesstion I wasasking is slightly different.
Let's say that each curved finished piece is made up of three segments glued together. if the joiint at segment A is X inches along the perimeter, and the second joint is at Y inches further and then the end is a total of X + Y + X, then are all of the four arches that compile the frame the same or might one be made of parts that were for instance, (X-1") + (Y + 3") + (X- 2") or some other variation that allowed those biscuited joints to be staggered?
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If you need to stagger the joints, you can do it by making an additional segment in your glue up and rotating the template. Here are a couple of drawings to illustrate.
Got a router table? Get a glue-joint cutter. Makes the serrated joints they use on finger-jointed lumber. Much stronger because the joint is at least 50% face grain instead of end grain. Takes a little more time than biscuits, but its about the strongest joint you can do. For glue, nothing really gives a clear glue line except epoxy. The joint just has to fit well to minimize it. Epoxy is probably a good choice. Titebond 2 or 3 is fine if you have a finish on it. Polyurethane is OK but messier. They have a light glue line. Resorcinal is better for water resistance but has a dark line. It sands the best. The others gum up sandpaper, but can still be sanded OK. Tung oil will not hold up well as an exterior finish. Teak oil has a fighting chance, but Marine Waterlox is better. The waterlox is more glossy than oil. Exterior, plan on recoating every couple years at least. High maintenance.
"For glue, nothing really gives a clear glue line except epoxy. "
Bob,
In my experience, epoxy ambers over time, gradually turning red. This coloration doesn't effect bond strength, but it will make the glue joint more visible over time if the joinery isn't exceptionally tight.
I'd be inclined to use Weldwood plastic cement (or one of the other urea-formaldehyde adhesives) in this application. In addition to being waterproof, the tan/beige color blends well with most wood - and can be tinted if desired. Like epoxy, they provide significantly more open time than Titebond.-Jazzdogg-
Whether you think you can, or you think you can't, you're right.
Guess I never noticed the discoloration since I've never left the epoxy exposed to the weather. The formaldehyde and resin glues are very good and waterproof. They sand better than anything else. Only reason I don't use them more often is the cure temperature. Needs to be really warm. 70 or 80 degrees and needs to be clamped for 24 hours usually. That's a problem in my shop during the winter so I use something that can be used year-round. Epoxy can have anywhere from 5 minutes to a couple hours open time and will cure well when its pretty cold.
I have use titebond two outside, poor choice of glue. I tried it with facsia boards that were mitered at the returns. I used4 biscuits in a 1x8 joint, all corners opened up in time. Not bad enough to replace , but no better looking if I did not glue them at all. Not familiar with titebond three, am familiar with gorrilla glue. Works well, no problems with it. I have used epoxy for some things, also works fine but more of a pita. Had no visible glue lines with gorilla glue. Piffin is correct that you mist one or both edges with water, mist the biscuits and they will swell .
mike